XGQT's blog: XGQT's blog

My current gitmessage template

Maciej Barć — Fri, 03 Jul 2026 14:30:00 UT

It is possible to configure git to use a extra helpful git message when inside the git commit editor.

#
# When committing follow those rules:
#   1. Use the Conventional Commits style when committing!
#      Follow this template:
#        > <type>[optional scope]: <description>
#        >
#        > [optional body]
#        >
#        > [optional footer(s)]
#      Allowed commit types are:
#        fix, feat, build,
#        chore, ci, docs,
#        style, refactor, perf,
#        test.
#      See also: https://www.conventionalcommits.org/en/v1.0.0/
#   2. Remember to add a "Signed-off-by"!
#      For example:
#        > Signed-off-by: John Smith <js@js.org>
#

Save that as .gitmessage on repo root.

Then wire it to local git config with:

1	git config --local commit.template .gitmessage

XGQT.Org gallery

Maciej Barć — Wed, 01 Jul 2026 21:30:00 UT

Sigal script
See also

My image gallery is up on xgqt.org/gallery.

It is a million times better than Instagram and also it has no likes or comments - that’s a feature!

I build it with Sigal which outputs to static HTML pages.

Sigal script

out="/var/www/xgqt.org/htdocs/gallery"
mkdir -p "${out}"
sigal build                         \
      --config ./sigal.conf.py      \
      --title Gallery               \
      ./pictures/ "${out}"          \
      "${@}"

Scribble hacks: insert module code

Maciej Barć — Sun, 28 Jun 2026 22:00:00 UT

get-module-content for showing module implementation
get-module-content usage inside Scribble
See also

get-module-content for showing module implementation

Normally Scribble, the Racket’s documentation tool, does not provide a way to see how a function/object/module is actually defined in the code. Just recently I wound a good-enough way to insert the whole content of the module we are documenting with Scribble.

Here’s my implementation:

(define (get-module-content module-name)
  (~> module-name
      string->symbol
      (module-path-index-join #false)
      module-path-index-resolve
      resolved-module-path-name
      file->lines
      (filter (lambda (s)
                (not (regexp-match-exact? #rx"^;.*" s))) _)
      (string-join "\n")
      string-trim))

The input is a module name in the form that you would use in absolute require form, except that it is a string, not a bare syntax.

get-module-content will reach out to Your Racket package database and find a module that you gave. It will read it and remove all comments. It returns a Racket string.

The string? returned by get-module-content can later be used to either extract some more info but it can be effectively used to insert the full module implementation block.

get-module-content usage inside Scribble

In Scribble I insert the module source code like so:

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The source code of this module:

@codeblock[@get-module-content{mypkg/utils/path}]

Common Project Layout, Version 1... A Rough Draft #1

Maciej Barć — Wed, 15 Apr 2026 18:00:00 UT

For CPL version 0 see common-project-layout-version–0. A template project for CPL v1 can be found at gitlab.com/xgqt/xgqt-misc-template-cplv1.

To solve the repository layout problem we propose this hierarchy:

separate the code from text/prose by clear distinction on top-level — thus the code dir
for code we create this structure:
- authoring — authoring scripts for developers
- copyright — copyright documents for the code
- integration — integration scripts, ie CI/CD scripts or Groovy sources for Jenkins
- source — versioned application/library sources, each major version is assigned a v<MAJOR> directory; this allows us to keep and maintain multiple versions, it is very reminiscent to having multiple package versions in a Ports (FreeBSD/Gentoo) repository
  - for the v<MAJOR> dirs we separate each bag of sources or scripts into its own directory, for example:
    - 3rd-party
    - admin
    - build-support
    - run
    - <APPNAME>-app
    - <APPNAME>-lib

Tutorial: PowerShell Modules in FSharp

Maciej Barć — Mon, 12 May 2025 16:47:03 UT

F# is a amazing functional language bridging C#/.NET ecosystem with OCaml and interactive programming. It has recently became by favorite language to create personal projects in. It both has additional security of strong typing, unlike Python or Ruby while keeping the functional and interactive properties of weak-typed languages. F# is truly a engineering marvel.

PowerShell 7 is the Open-Source implementation of the old Windows PowerShell that is also cross-platform and can be used for scripting and automation. It’s Object-orientation makes an amazing extension capability compared to Bash.

You can use the F# language to create PowerShell modules. Normally PS Modules are written in C# but since the interop between .NET languages is insanely fluent one can just swap C# for F#.

Creating new project

1 2	mkdir -p ~/source/temporary/powershell-modules/fs-example cd ~/source/temporary/powershell-modules/fs-example

Dotnet ClassLib

Init new F# Class project:

1	dotnet new classlib --language "F#"

Dependencies

Add dependency on Powershell interaction library:

1	dotnet add package PowerShellStandard.Library --version 5.1.1

F# interaction with PowerShell

Let’s rewrite Library.fs to contain:

namespace FsExample.PowerShell

open System.Management.Automation

[<Cmdlet(VerbsCommon.Format, "FsExample")>]
type FsExample() =
    inherit PSCmdlet()

    [<Parameter>]
    [<ValidateNotNullOrEmpty>]
    member val Name: string = "Me" with get, set

    override this.BeginProcessing() =
        printfn "Hello %s" this.Name

Then, change RootNamespace to the main module name, that is FsExample.PowerShell.

We need to copy all assemblies to output. Add <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net9.0</TargetFramework>
    <RootNamespace>FsExample.PowerShell</RootNamespace>
    <GenerateDocumentationFile>true</GenerateDocumentationFile>

    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
  </PropertyGroup>

  <!-- Snip ... -->

</Project>

PowerShell library

Create PSModuleAssets directory:

1 2	mkdir -p PSModuleAssets cd PSModuleAssets

The main module file will in turn load the DLL compiled form above F# code.

Create main module file - fs-example.psm1:

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#!/usr/bin/env -S pwsh -NoLogo -NoProfile -NonInteractive

Import-Module "$PSScriptRoot/fs-example.dll"

We then need to create the main manifest file fs-example.psd1.

Path - relative path to output the manifest,
RootModule - relative module path to load on module import,
ModuleVersion, Description, Author and Copyright are some of standard metadata fields,
AliasesToExport, CmdletsToExport, DscResourcesToExport, FunctionsToExport and VariablesToExport are either globs or lists that tell what functions will be available on module load, for simplicity we will just specify a glob expression '*'.

New-ModuleManifest -Path ./fs-example.psd1 -RootModule ./fs-example.psm1 `
    -ModuleVersion "1.0.0" `
    -Description "FSharp example module" `
    -Author "Me" -Copyright "Copyright (c) 2025, Me" `
    -AliasesToExport '*' -CmdletsToExport '*' `
    -DscResourcesToExport '*' -FunctionsToExport '*' -VariablesToExport '*'

Copying PowerShell assets

Following ItemGroup will copy all files from PSModuleAssets to the output directory:

<Project Sdk="Microsoft.NET.Sdk">

  <!-- Snip ... -->

  <ItemGroup>
    <None Include="PSModuleAssets/*.*">
      <Link>%(Filename)%(Extension)</Link>
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </None>
  </ItemGroup>

  <!-- Snip ... -->

</Project>

Building the F# module

Clean up the old builds:

1 2	rm -fr ./psrepository rm -fr ./out-module/fs-example

Dotnet-Build

And then build the module:

1 2	dotnet restore dotnet build --configuration Release --output ./out-module/fs-example

Language locality bug

You have to use the en-US locale when publishing PowerShell modules.

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$env:LANG = "en_US.UTF-8"
$env:LANGUAGE = "en_US.UTF-8"
$env:LC_MESSAGES = "en_US.utf8"

Installation

Remove old registered PowerShell repository:

1	try { Unregister-PSRepository -Name fs-example } catch { }

Register-PSRepository and Publish-Module

This quite complicated script will:

set up a PowerShell repository in current location,
register the PowerShell repository,
publish the module into the PowerShell repository,
install that published module from the PowerShell repository.

$repo = "fs-example"
$repoPath = "$pwd/psrepository/fs-example"

New-Item -ItemType Directory -Path $repoPath | Out-Null
Register-PSRepository -InstallationPolicy Trusted -Name $repo -SourceLocation $repoPath

Publish-Module -Verbose -Path $pwd/out-module/fs-example -Repository $repo
Install-Module -Scope CurrentUser -Force -Verbose -Name fs-example -Repository $repo

Removal

Uninstall-Module

Just call Uninstall-Module to remove any PowerShell module.

1	Uninstall-Module -Name fs-example

Usage in the REPL

Import-Module

Import it with Import-Module.

1	Import-Module -Verbose fs-example -Force

Finally - use Format-FsExample

Remember the above F# function that was defined in the class?

1 2	[<Cmdlet(VerbsCommon.Format, "FsExample")>] type FsExample()

It will be now available under the name composed of the “common verb” and a secondary part, so Format-FsExample.

Try it:

1	Format-FsExample -Name Maciej

Interacting with OneDrive in Nextcloud by using RClone

Maciej Barć — Thu, 07 Nov 2024 15:57:37 UT

How it works

There will be a FUSE OneDrive filesystem mounted on the machine Nextcloud runs on,
You configure filesystem-local “External storage” and point to the mountpoint of a cloud drive (in this case OneDrive),
users connected via Nextcloud Client will have a option to sync any chosen files from the External storage as if they were Nextcloud-owned files.

Benefits

There are some benefits from connecting OneDrive to Nextcloud:

faster cached sync than by normal straight-to OneDrive connection - files will be pushed to Nextcloud and then uploaded to Nextcloud, this will take less time than uploading straight to OneDrive because of Microsoft OneDrive rate-limiting the uploads (especially in case of larger files),
clients of Nextcloud do not have to configure any OneDrive connection,
you will be able to have two-way sync of your OneDrive files (currently two-way sync on the RClone side is experimental, this will use Nextcloud’s two-way sync mechanism).

Set up RClone

First You will have to set up RClone. Connect to your cloud of choice and then copy the config to a location that will be readable by a service that mounts a given cloud drive.

For OneDrive I use /usr/local/share/rclone/config/rclone.conf that is accessible only to the apache user.

The config will look something like this:

[OneDrive]
type = onedrive
region = global
token = *REDACTED*
drive_id = *REDACTED*
drive_type = personal

Mounting OneDrive

I created this helper script (in /usr/local/bin/rclone-mount.sh):

#!/bin/sh

set -e
set -u
trap "exit 130" INT

conf_path="${1}"

local_user="${2}"
local_path="${3}"

cloud_name="${4}"
cloud_path="${5}"

log_dir="/var/log/rclone"
log_file="${log_dir}/rclone-mount-${local_user}-${cloud_name}.log"

mkdir -p "${log_dir}"
touch "${log_file}"

chmod a+r "${log_file}"
chown "${local_user}" "${log_file}"

exec rclone                                         \
     --default-permissions                          \
     --allow-other                                  \
     --verbose                                      \
     --vfs-cache-mode full                          \
     --config "${conf_path}"                        \
     mount                                          \
     "${cloud_name}:${cloud_path}" "${local_path}"  \
     >> "${log_file}" 2>&1

Then, I use it in a OpenRC service like this (/etc/init.d/mount-OneDrive):

#!/sbin/openrc-run

conf_path="/usr/local/share/rclone/config/rclone.conf"

cloud_name="OneDrive"
cloud_path="/"

local_user="apache"
local_path="/mnt/${cloud_name}"

command="/usr/local/bin/rclone-mount.sh"
command_args="${conf_path} ${local_user} ${local_path} ${cloud_name} ${cloud_path}"

command_background="false"
command_user="${local_user}:$(id -g -n ${local_user})"
supervisor="supervise-daemon"

depend() {
    need net
}

start_pre() {
    ebegin "Unmounting leftovers from ${local_path} before service start"
    umount "${local_path}"
    eend 0
}

stop_post() {
    ebegin "Unmounting leftovers from ${local_path} after service stop"
    umount "${local_path}"
    eend 0
}

Enabling the RClone service

Set up directories and correct permissions:

mkdir -p /usr/local/share/rclone/config
chown -R apache:apache /usr/local/share/rclone/config

mkdir -p /var/log/rclone
chown -R apache:apache /var/log/rclone

Do not forget to make the mount service script executable:

1	chmod +x /etc/init.d/mount-OneDrive

Enable and start this service on OpenRC:

1 2	rc-update add mount-OneDrive default rc-service mount-OneDrive start

Drive permissions

RClone mounts cloud drives by using FUSE. To have the RClone option --allow-other available in order to allow root to access the drive you will have to modify the FUSE config file (/etc/fuse.conf) - add user_allow_other.

Nextcloud configuration

Download and enable the “External storage” app. Then, in “Administration” settings add a external storage:

name: ExternalStorage_OneDrive
type: Local
authentication: None
configuration: /mnt/OneDrive
available for: YOUR USER

GHC 9.8 and Cabal 3.10.3 on Gentoo Linux

Maciej Barć — Thu, 07 Nov 2024 15:02:31 UT

The official ::gentoo repository currently contains only GHC on version 9.2.8. To install newer GHC one has to either download/build themselves or use the ::haskell overlay (https://github.com/gentoo-haskell/gentoo-haskell).

Enable the ::haskell overlay

Enable:

1	eselect repository enable haskell

Sync:

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emerge --sync haskell
egencache --update --repo haskell --jobs 12 --load 6
eix-update

Unmask needed packages

Add to /etc/portage/package.unmask/0000_hs.conf

<dev-lang/ghc-9.9

<dev-haskell/cabal-3.11
<dev-haskell/cabal-install-3.11
<dev-haskell/cabal-install-solver-3.11
<dev-haskell/cabal-syntax-3.11
<dev-haskell/text-2.2
<dev-haskell/parsec-3.1.18

Add to /etc/portage/package.accept_keywords/0000_hs.conf

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app-admin/haskell-updater
dev-haskell/*
dev-lang/ghc

Install

1	emerge --ask --verbose ">=dev-lang/ghc-9.8" ">=dev-haskell/cabal-install-3.10"

Build of GHC 9.8 takes around ~2 hours on a 8-core laptop-grade CPU.

Bonus: masking packages from ::haskell

If you want to exclude a given version from the ::haskell overly from being installed/updated, then you can add a similar line(s) to /etc/portage/package.mask/0000_hs.conf:

1	app-emacs/haskell-mode::haskell

Forgotten SysStat

Maciej Barć — Mon, 28 Oct 2024 21:35:15 UT

SysStat is a amazing tool. In the age where telegraf and grafana are all the rage everybody forgot about the good old sysstat.

Selected command examples

iostat -d -p nvme0n1 3 - disk I/O for a NVME drive (nvme0n1),
sar -n DEV 3 - network throughput,
sar -h -r 3 - memory usage,
sar -P ALL 3 - CPU utilization
sar -q 3 - system load levels,
sar -A 3 - all the metrics.

Gathered info

qlist app-admin/sysstat | grep /usr/bin/

The app-admin/sysstat contains the following binaries and their respective statistic fields:

sar - general utilization statistics,
cifsiostat - CIFS,
iostat - device input/output,
mpstat - processors,
pidstat - Linux tasks,
tapestat - tape (yes, the real tape disks).

Installation

Gentoo

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emerge --noreplace --verbose sys-process/cronie app-admin/sysstat
rc-service cronie start
rc-update add cronie default

Files

By default (on Gentoo): * sa (the collector) saves statistics to /var/log/sa, * /etc/sysstat is the configuration file * cron jobs are run via the *system* cronjob table.

Tag the releases

Maciej Barć — Thu, 03 Oct 2024 15:43:33 UT

Tag your releases!

There were so many times when I wanted to use some package, it has a version on repology, but when I open the project’s repo there are no tags.

Nowadays it is extremely easy to bump software versions according to semantic versioning and also to tag them, that it should go without saying that most OSS and proprietary projects could also follow that workflow.

There are many projects both language-specific and agnostic to manage the release (and tagging) process. My favorite agnostic one is tbump and I highly recommend it.

Install Bazel ZSH completion

Maciej Barć — Fri, 02 Aug 2024 18:20:08 UT

(
    repo="bazelbuild/bazel";
    raw="https://raw.githubusercontent.com/${repo}";
    url="${raw}/master/scripts/zsh_completion/_bazel";
    site_functions="/usr/share/zsh/site-functions";

    wget "${url}" -O ${site_functions}/_bazel
)

Afterwards, restart your ZSH shell session.

This also works if you have bazelisk installed but bazel has to be symlinked to the bazelisk executable path.

Do not split make.conf

Maciej Barć — Tue, 09 Jul 2024 20:00:59 UT

I made a mistake when splitting my Portage make.conf file, having it as one file instead of a directly with many small files is a lot easier to maintain.

Portage allows users to split all of files inside /etc/portage such as make.conf, package.use, package.mask and other into groups of files contained in directories of the same name. This is very helpful when using automation to add some wanted configuration. But in case of make.conf it becomes a “form over function” issue.

I would also recommend to keep make.conf as simple as possible, without useless overrides and variable reassignment.

Bonus: config

And of course, this is my current /etc/portage/make.conf of my main dev machine:

BINPKG_FORMAT="gpkg"
CCACHE_DIR="/var/cache/ccache"
EMERGE_WARNING_DELAY="0"
LC_MESSAGES="C"

PORTAGE_NICENESS="10"
PORTAGE_WORKDIR_MODE="0775"

PORTAGE_LOGDIR="${EPREFIX}/var/log/portage"
PORTAGE_ELOG_CLASSES="warn error log"
PORTAGE_ELOG_SYSTEM="save"

QUICKPKG_DEFAULT_OPTS="--include-config=y --umask=0003"
MAKEOPTS="--jobs=7 --load-average=6"

COMMON_FLAGS="
  -march=znver1 -O2 -falign-functions=32
  -fstack-clash-protection -fstack-protector-strong
  -fdiagnostics-color=always -frecord-gcc-switches -pipe"

ADAFLAGS="${COMMON_FLAGS}"
CFLAGS="${COMMON_FLAGS}"
CXXFLAGS="${COMMON_FLAGS}"
FCFLAGS="${COMMON_FLAGS}"
FFLAGS="${COMMON_FLAGS}"

CARGO_TERM_VERBOSE="false"
RUSTFLAGS="-C opt-level=3 -C debuginfo=0"

LDFLAGS="${LDFLAGS} -Wl,--defsym=__gentoo_check_ldflags__=0"

L10N="en de pl"
VIDEO_CARDS="amdgpu radeon radeonsi"

CPU_FLAGS_X86="
  aes avx avx2 f16c fma3 mmx mmxext pclmul popcnt
  sha sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3"

EMERGE_DEFAULT_OPTS="
  --binpkg-changed-deps=y --binpkg-respect-use=y
  --nospinner --keep-going=y
  --jobs=3 --load-average=8"

GENTOO_MIRRORS="
  https://mirror.leaseweb.com/gentoo/
  https://gentoo.osuosl.org/
  https://distfiles.gentoo.org/"

FEATURES="
  userpriv usersandbox usersync
  downgrade-backup unmerge-backup binpkg-multi-instance buildsyspkg
  parallel-fetch parallel-install
  ccache
  -binpkg-logs -ebuild-locks"

USE="
  custom-cflags custom-optimization firmware initramfs vaapi vulkan
  -bindist -zeroconf"

The dilemma between Gentoo and Nixos

Maciej Barć — Sat, 08 Jun 2024 10:55:18 UT

The dilemma between #Gentoo and #NixOS is this:

The most important value of #Gentoo is configuration/customization and reproducibility comes 2nd.

In case of NixOS those value are reversed. The most important to NixOS is ability to reproduce given setup.

Both of those systems will suit users that value control over their systems very highly (unlike, say, Ubuntu - where the most important value is convenience), but the tie-breaking is between what value out of those two should come 1st.

Imported via Fedimpost from emacs.ch/@xgqt/112581104037953790

Installing unstable GIMP with Flatpak

Maciej Barć — Fri, 17 May 2024 21:35:17 UT

Add Flathub-Beta

Add the Flathub-Beta remote repository:

1	flatpak remote-add --user flathub-beta https://flathub.org/beta-repo/flathub-beta.flatpakrepo

Install GIMP beta

Install org.gimp.GIMP form flathub-beta:

1	flatpak install --assumeyes --user flathub-beta org.gimp.GIMP

Run GIMP

If you have other GIMP versions installed you will have to specify the “beta” version with //beta.

1	flatpak run org.gimp.GIMP//beta

Otherwise you can just run:

1	flatpak run org.gimp.GIMP

Also, in the desktop menus (like KRunner) this version of GIMP will have (beta) in its name so there is no chance to miss it.

Change location of intermediate objects in .NET

Maciej Barć — Wed, 06 Mar 2024 22:32:17 UT

.NET creates the so-called intermediate objects while building .NET projects, those are located in the “bin” and “obj” directories. The default is not very satisfying, primarily because if a program from a different machine or a container modifies those, then any cached file system paths that are encoded in the objects will be broken. But also it is probably mostly a legacy behavior to have them split between “bin” and “obj” directories.

I prefer for them to say in one - ".cache", because that’s that they are - cache. With the following configuration objects will be stored inside the ".cache" directory. Furthermore, the objects produced by the native machine in the “native” subdirectory and the ones produced by container software in “container” subdirectory.

<PropertyGroup>
  <CachePath>.\.cache\native</CachePath>
  <CachePath Condition="'$(DOTNET_RUNNING_IN_CONTAINER)' == 'true'">.\.cache\container</CachePath>
  <MSBUildProjectExtensionsPath>$(CachePath)\obj\</MSBUildProjectExtensionsPath>
  <BaseIntermediateOutputPath>$(CachePath)\obj\</BaseIntermediateOutputPath>
  <BaseOutputPath>$(CachePath)\bin\</BaseOutputPath>
</PropertyGroup>

If anybody want to go hardcore and cache the intermediate objects based on the RID or architecture triplet, then this can also be done, for example, by adding environment variables to the path.

Safer Nix installation

Maciej Barć — Mon, 12 Feb 2024 20:28:31 UT

Nix is useful for quickly testing out software and providing a strict environment that can be shared between people.

Today I’m trying out Nix again, this time I want to do it my way.

Installation process

Nix store

I know Nix needs “Nix store” installation on / (the system root).

Create it manually to prevent the installation script from calling sudo. 1st I switch to the root account, and then I run:

1 2	mkdir -p -m 0755 /nix chown -R xy:xy /nix

Running the install script

Download the Nix install script and examine the contents.

1	curl -L https://nixos.org/nix/install > nix_install.sh

Then, run it with --no-daemon to prevent it running as system service.

1	sh ./nix_install.sh --no-daemon

performing a single-user installation of Nix...
copying Nix to /nix/store...
installing 'nix-2.20.1'
building '/nix/store/1ahlg3bviy174d6ig1gn393c23sqlki6-user-environment.drv'...
unpacking channels...
modifying /home/xy/.bash_profile...
modifying /home/xy/.zshenv...
placing /home/xy/.config/fish/conf.d/nix.fish...

Installation finished!  To ensure that the necessary environment
variables are set, either log in again, or type

. /home/xy/.nix-profile/etc/profile.d/nix.fish

in your shell.

Wait!

modifying /home/xy/.bash_profile...
modifying /home/xy/.zshenv...
placing /home/xy/.config/fish/conf.d/nix.fish...

That’s very rude!

Stopping Nix from making a mess

I need to prevent Nix from mess up with my environment when I do not want it to. Nix puts some code into the Bash, ZSH and Fish initialization files during installation to ease it’s use. I do not want that since I do not want Nix to meddle with my environment without me knowing it.

I keep my .bash_profile and .zshenv in a stow-managed git repo so I can just cd into my repo and do git reset --hard, but for you will have to revert those files to their old forms manually.

Playing with Nix

We do not have nix in PATH but we still can launch it. Nix executables are located inside ~/.nix-profile/bin/.

By invoking nix-shell one can create a ephemeral environment containing only packages specified after the -p flag. I always add -p nix to have the Nix tools available also inside the spawned environment.

I will test out chibi (small Scheme interpreter) + rlwrap (REPL support for software lacking it) inside a Nix ephemeral environment:

1	~/.nix-profile/bin/nix-shell -p nix chibi rlwrap

Inside the spawned shell:

1	rlwrap chibi-scheme

In the chibi REPL, let’s see the contents of the PATH environment variable:

1	(get-environment-variable "PATH")

And exit the Scheme REPL:

(exit)

After the playtime, run garbage collection:

1	~/.nix-profile/bin/nix-collect-garbage

.NET in Gentoo in 2023

Maciej Barć — Sun, 17 Dec 2023 21:59:12 UT

.NET ecosystem in Gentoo in year 2023

The Gentoo Dotnet project introduced better support for building .NET-based software using the nuget, dotnet-pkg-base and dotnet-pkg eclasses. This opened new opportunities of bringing new packages depending on .NET ecosystem to the official Gentoo ebuild repository and helping developers that use dotnet-sdk on Gentoo.

New software requiring .NET is constantly being added to the main Gentoo tree, among others that is:

PowerShell for Linux,
Denaro — finance application,
Ryujinx — NS emulator,
OpenRA — RTS engine for Command & Conquer, Red Alert and Dune2k,
Pinta — graphics program,
Pablodraw — Ansi, Ascii and RIPscrip art editor,
Dafny — verification-aware programming language
many packages aimed straight at developing .NET projects.

Dotnet project is also looking for new maintainers and users who are willing to help out here and there. Current state of .NET in Gentoo is very good but we can still do a lot better.

Special thanks to people who helped out

Links to bugs and announcements

Bugs
- gentoo-dotnet–2023/1
- 900597
Github PRs
- 21112
- 21451
- 29309
- 32109
- 33940
Active Gentoo .NET projects

Portage Continuous Delivery

Maciej Barć — Sat, 16 Dec 2023 23:50:15 UT

Portage as a CD system

This is a very simple way to use any system with Portage installed as a Continuous Delivery server.

I think for a testing environment this is a valid solution to consider.

Create a repository of software used in your organization

Those articles from the Gentoo Wiki describe how to create a custom ebuild repository (overlay) pretty well:

Set up your repo with eselect-repository

Install the my-org repository:

1	eselect repository add my-org git https://git.my-org.local/portage/my-org.git

Sync my-org:

1	emerge --sync my-org

Install live packages of a your software

First, enable live packages (keywordless) for your my-org repo:

1	echo '/::my-org' >> /etc/portage/package.accept_keywords/0000_repo_my-org.conf

Install some packages from my-org:

1	emerge -av "=mycategory/mysoftware-9999"

Install smart-live-rebuild

smart-live-rebuild can automatically update live software packages that use git as their source URL.

Set up cron to run smart-live-rebuild

Refresh your my-org repository every hour:

1	0 /1 * * emerge --sync my-org

Refresh the main Gentoo tree every other 6th hour:

1	0 /6 * * emerge --sync gentoo

Run smart-live-rebuild every other 3rd hour:

1	0 /3 * * smart-live-rebuild

Restarting services after update

All-in-one script

You can either restart all services after successful update:

File: /opt/update.sh

#!/bin/sh

set -e

smart-live-rebuild

systemctl restart my-service-1.service
systemctl restart my-service-2.service

Crontab:

1	0 /3 * * /opt/update.sh

Via ebuilds pkg_ functions

File: my-service-1.ebuild

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pkg_postinst() {
    systemctl restart my-service-1.service
}

More about pkg_postinst:

Example Gentoo overlays

Firefox is still the best browser. Deal with it Google!

Maciej Barć — Tue, 21 Nov 2023 23:40:59 UT

Firefox began as the first open source browser to live through the browser wars, overcoming Microsoft’s Internet Explorer and continues to deliver competition-smashing technology to this day.

Chromium code

The only advantages of Chromium are that it was adopted by Electron and spread partially because of a more liberal license and Google’s own efforts.

Google will never be able to cope with the worst imaginable code base of Chromium.

Chromium is near-impossible to compile

On a 4cores/8threads Ryzen CPU Chromium compiles in ~12h and requires at least 20GB of disk space for build. At the same time Firefox compiles in ~1.5h and requires ~8GB for disk space.

Programming language adoption

Additionally Firefox team was able to rewrite a very large portion of Firefox codebase in Rust which improved the browser’s safety. There were attempts to add rust to Chromium but they all are in more of a addon-like fashion.

Porting to UNIXes

Because Chromium is extremely large it’s very hard to port and maintain for Linux and BSD based systems. There were numerous bugs with Chromium’s UI on Linux that cause crashes on pressing random controls. I believe Google has no Linux testers beside the “free software freeloaders” (wink, wink, IBM :P).

Anti-competition

This days Google has to result to dirty tactics where certain Google-owned websites would either refuse to work on Firefox or give a fake performance hit that is entirely caused by malicious JavaScript code.

Several popular FOSS-related sources have covered this news recently, check them out on the WWW.

I glued together Tramp and process sentinel and created a wr...

Maciej Barć — Wed, 25 Oct 2023 19:45:49 UT

I glued together #GNU #Emacs Tramp and process sentinel and created a wrapper around the (now OSS) devcontainers command.

Project URL: https://gitlab.com/xgqt/xgqt-elisp-lib-devcontainer

Imported via Fedimpost from emacs.ch/@xgqt/111297845630025827

Common Project Layout, version 0

Maciej Barć — Tue, 17 Oct 2023 19:45:50 UT

This is a tongue-in-cheek “draft” for Common Project Layout, version 0. It will probably never become any sort of adopted standard but I think it is good to share some ideas that I had while working on this.

Definition

Common Project Layout (CPL) is a set of good practices for structuring medium-to-large monorepo-like software repositories.

Benefits

CPL helps with code organization. It can be a good “framework” (in a very loose meaning of this word) to modularize product components.

It can make large repositories easier to work with and understand.

Upfront limitations

CPL is strictly designed for “hosting” software and all the non-code assets are left up to the engineers to decide their location.

For example branding assets could be put into the Branding top-level directory, but on the other hand are we sure they will stay the same with major version?

Since we can agree that we consider documentation “producers” (not the produced artifacts) to be code we could also acknowledge that some assets could have their own versioned subproject.

Requirements

Versioning

CPL requires that the software is versioned inside directories whose names include the version. Recommended pattern is to name directories vMAJOR where MAJOR is either the current tagged major version or one that will be if no tags exist. It is also recommended to group the vMAJOR directories under one common directory, for example Source.

Subprojects

The vMAJOR could theoretically contain all the source code mixed together but it should be grouped and organized by their purpose.

Subproject is defined as a directory inside a versioned (vMAJOR) directory. “Versioned subproject” and “subproject” are synonymous to CPL.

To mark the purpose of a subproject, whether it is to be used as a helper or as a “container” for source that is actually exposed (or binaries created from it), it should be adequately named.

For helpers name does not matter but for source subproject it should be prefixed by project name.

For example we could have this layout:

Source/
└── v1/
    ├── Makefile
    ├── VERSION
    ├── admin/
    ├── make/
    ├── my-project-app/
    └── my-project-util/

In the above example my-project-app and my-project-lib are the source subproject and admin and make are subproject that are there only to help in building, managing and deploying the actual source subprojects.

At the and it is up to the engineer to choose if something is considered a source subproject. For example: If we have a helper subproject that all it does is hold Docker / Podman files for creating a development container what should we name it? As of now I had named them PROJECT-dev-container.

Recommendations

Make and admin

I think it is a good practice for each vMAJOR to have a Makefile, or equivalent in other build system, that will call scripts inside vMAJOR/admin directory that each take care of some small / specific task.

For example the vMAJOR/Makefile recipe for build can call admin/build_my_project_app.py and admin/build_my_project_lib.py. Each those scripts would call the “real” build system specific to the subproject they act upon.

VERSION file

It is nice to have a VERSION file in the vMAJOR directory. It can be reused by build tools and also to show what was the last version worked upon inside vMAJOR, the latest git tag can either be put on different major version or simply not be there yet.

References

See those repositories for referencing the CPL layout:

I created a tool that allows to import Fediverse posts to bl...

Maciej Barć — Sun, 08 Oct 2023 06:01:55 UT

I created a tool that allows to import Fediverse posts to blogging frameworks (currently Racket Frog). So it allows to transition selected posts from micro-blogging to real blogging :P

https://gitlab.com/xgqt/xgqt-csharp-app-fedimpost

It’s written in #CSharp and used #DotNET 6.0

Imported via Fedimpost from emacs.ch/@xgqt/111198346664102355

I have nothing against people who make desktop apps as webap...

Maciej Barć — Sat, 07 Oct 2023 22:54:10 UT

I have nothing against people who make desktop apps as webapps as long as webkitgtk or qtwebengine is used. But why the hell would you use electron in our lord’s year 2023 when in addition to webkitgtk you have libs that use it underneath and ease the dev experience.

Imported via Fedimpost from emacs.ch/@xgqt/111196664631036872

Using gzexe for shipping Racket executables

Maciej Barć — Thu, 28 Sep 2023 18:18:12 UT

Racket executables made by raco exe are known to be quite large. One of tools that can be used to help reduce the size of produced binaries is the gzexe program.

gzexe is a tool that can compress a executable binary. It can be acquired by installing gzip on most Linux distributions (included in the app-arch/gzip package on Gentoo).

Creating a hello-world executable with Racket

Write following contents to hello-world.rkt file:

#lang racket/base

(define (main)
  (displayln "It REPLs. Ship it!"))

(module+ main
  (main))

To make a binary run:

1	raco exe --orig-exe -v -o hello-world hello-world.rkt

The file hello-world will be produced.

This is what file hello-world says about it:

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hello-world: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV),
dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2,
for GNU/Linux 3.2.0, stripped

This “small” executable weights 46 MB!

In comparison busybox weights around 2 MB.

Compressing with gzexe

Keep in mind that gzexe will overwrite the compressed file and create a backup with appended "~".

1	gzexe hello-world

And this gives us only 8,5 MB. Nice!

In comparison bazel, which is a single-binary build system written in JAVA, executable takes 33 MB on my Gentoo machine. I tried compressing it with gzexe and it reduces it only by 10%, to around 29 MB.

gzexeis not a silver bullet but with Racket exes it works very nicely.

Using light theme in a sunny day feels a lot better than usi...

Maciej Barć — Thu, 28 Sep 2023 09:14:44 UT

Using light theme in a sunny day feels a lot better than using a dark theme.

I use “ef-day” in #Emacs and “Solarized Light” in other IDEs and terminals.

Imported via Fedimpost from emacs.ch/@xgqt/111142481730093470

Genkernel in 2023

Maciej Barć — Sat, 29 Jul 2023 15:10:35 UT

I really wanted to look into the new kernel building solutions for Gentoo and maybe migrate to dracut, but last time I tried, ~1.5 years ago, the initreamfs was now working for me.

And now in 2023 I’m still running genkernel for my personal boxes as well as other servers running Gentoo.

I guess some short term solutions really become defined tools :P

So this is how I rebuild my kernel nowadays:

Copy old config

1 2	cd /usr/src cp linux-6.1.38-gentoo/.config linux-6.1.41-gentoo/

Remove old kernel build directories
1

rm -r linux-6.1.31-gentoo

Run initial preparation

1	( eselect kernel set 1 && cd /usr/src/linux && make olddefconfig )

Call genkernel

genkernel                                                       \
    --no-menuconfig                                             \
    --no-clean                                                  \
    --no-clear-cachedir                                         \
    --no-cleanup                                                \
    --no-mrproper                                               \
    --lvm                                                       \
    --luks                                                      \
    --mdadm                                                     \
    --nfs                                                       \
    --kernel-localversion="-$(hostname)-$(date '+%Y.%m.%d')"    \
    all

Rebuild the modules

If in your /etc/genkernel.conf you have MODULEREBUILD turned off, then also call emerge:
1

emerge -1 @module-rebuild

Shell script setup

Maciej Barć — Sun, 16 Jul 2023 21:12:00 UT

Good practices

Use sh

If you do not need bash features, then use sh, it is installed on every UNIX-like system.

#!/bin/sh

Exit on failure

Shell scripts continue even if a command returns error. To fail right away use:

set -e

Trap C-c

Catch Control-c and exit.

1	trap "exit 130" INT

Use script directory

Assume we are executing a script from directory /Admin, where / is the root of a given project directory.

1 2	script_path="${0}" script_root="$(dirname "${script_path}")"

We can use ${script_root} to call other scripts form the Admin directory, but we can also use it to relate to the /.

1
2
3

project_root="$(realpath "${script_root}/../")"
echo "[INFO] Entering directory: ${project_root}"
cd "${project_root}"

So with above we can run commands form / (repository root). Like for example make and other:

1 2	make python3 ./Admin/serve_1.py

Even better

Use Python for repository maintenance scripts.

from os import chdir
from os import path

from subprocess import run
from sys import argv

script_path = path.realpath(__file__)
script_root = path.dirname(script_path)
project_root = path.realpath(path.join(script_root, ".."))

print(f" * Entering directory: {project_root}")
chdir(project_root)

leftover_args = argv[1::]
command_arguments = ["make"] + leftover_args

cmd_string = " ".join(command_arguments)
print(f" * Executing command: {cmd_string}")
run(command_arguments, check=True)

ELisp ebuilds good practices

Maciej Barć — Sat, 15 Jul 2023 17:25:25 UT

Check load path

Some Elisp package compilation failures are caused by not setting the loadpath correctly. It mostly happens when you compile source from a directory that is not the current working directory. For example:

1	elisp-compile elisp/*.el

In most cases you can cd or override the S variable to set it to location where ELisp source resides.

But in other cases you can append to load path the directory with source, see:

1	BYTECOMPFLAGS="${BYTECOMPFLAGS} -L elisp" elisp-compile elisp/*.el

Do not rename auto-generated autoload file

elisp-make-autoload-file allows to name the generated autoload file. For sake of easier debugging and writing Gentoo SITEFILEs, please do not rename the generated file.

The name of that file should always be ${PN}-autoloads.el.

Use new elisp-enable-tests function

elisp-enable-tests allows to set up IUSE, RESTRICT, BDEPEND and the test runner function for running tests with the specified test runner.

The 1st (test-runner) argument must be one of:

buttercup — for buttercup provided via app-emacs/buttercup,
ert-runner — for ert-runner provided via app-emacs/ert-runner,
ert — for ERT, the built-in GNU Emacs test utility.

The 2nd argument is the directory where test are located, the leftover arguments are passed to the selected test runner.

Example:

EAPI=8

inherit elisp

# Other package settings ...

SITEFILE="50${PN}-gentoo.el"
DOCS=( README.md )

elisp-enable-tests buttercup test

Remove empty SITEFILEs

Recently a feature was added to elisp.eclass that will cause build process to generate the required SITEFILE with boilerplate code if it does not exist.

So if your SITEFILE looked like this:

1	(add-to-list 'load-path "@SITELISP@")

… then, you can just remove that file.

But remember to keep the SITEFILE variable inside your ebuild:

1	SITEFILE="50${PN}-gentoo.el"

Remove pkg.el files

The *-pkg.el files are useless to Gentoo distribution model of Emacs Lisp packages and should be removed. It is as simple as adding this line to a ebuild:

1	ELISP_REMOVE="${PN}-pkg.el"

Beware that some packages will try to find their ${PN}-pkg.el file, but in most cases this will show up in failing package tests.

Use official repository

It is tedious to repackage Elpa tarballs, so use the official upstream even if you have to snapshot a specific commit.

To snapshot GitHub repos you would generally use this code:

# First check if we have the correct version to prevent
# autobumping package version without changing the commit.
[[ ${PV} == *_p20220325 ]] && COMMIT=65c496d3d1d1298345beb9845840067bffb2ffd8

# Use correct URL that supports snapshots.
SRC_URI="https://github.com/domtronn/${PN}/archive/${COMMIT}.tar.gz
    -> ${P}.tar.gz"

# Override the temporary build directory variable.
S="${WORKDIR}"/${PN}-${COMMIT}

Include live version support

We do not want to be worse than the Melpa unstable :D

So, why not allow the given package to be used live?

Even if you do not push the live package to the overlay, please include support for it.

if [[ ${PV} == *9999* ]] ; then
    inherit git-r3
    EGIT_REPO_URI="https://github.com/example/${PN}.git"
else
    SRC_URI="https://github.com/example/${PN}/archive/${PV}.tar.gz
        -> ${P}.tar.gz"
    KEYWORDS="~amd64 ~x86"
fi

Ask for tags

Git is good, git tags are good. In case if upstream does not tag their package or just forgets to, kindly ask them to create a git tag when bumping Emacs package versions.

Debugging Frog blog with syntax macros

Maciej Barć — Sat, 15 Jul 2023 16:24:16 UT

Constructing debugging syntax

I wanted to echo parameter values when I set them in my blog’s frog.rkt config file.

Nothing simpler in Racket!

First I create this macro for echoing a single parameter value when it is set:

(define-syntax-rule (verbose-set-parameter parameter-id parameter-value)
  (begin
    ;; Set the parameter.
    (parameter-id parameter-value)

    ;; Then call the parameter and print it's value.
    ;; The "'parameter-id" is special syntax
    ;; for turning a "parameter-id" identifier to a symbol.
    ;; We can also write it like:
    ;; > (quote parameter-id)
    ;; to be less confusing.
    (printf "[DEBUG] (~a ~v)\n" 'parameter-id (parameter-id))))

then, I create a wrapper for above macro that can take multiple parameter pairs:

(define-syntax-rule (verbose-set-parameters (parameter-id parameter-value) ...)
  (begin
    ;; Unpack a chain of "(parameter-id parameter-value)" pairs
    ;; using the "..." syntax.
    (verbose-set-parameter parameter-id parameter-value) ...))

Using the macro

Afterwards we can call it like so:

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(verbose-set-parameters
 (current-title "XGQT's blog")
 (current-author "Maciej Barć"))

Notice that even the form of setting a parameter, that is (parameter-procedure "value"), remains the same, but in reality it is just similar to how the syntax macro pattern-matches on it.

Inspecting macro expansion

In racket-mode inside GNU Emacs we can inspect the macro expansion with racket-expand-region. Stepping through the expansion provided this result:

(begin
  (begin
    (current-title "XGQT's blog")
    (printf "[DEBUG] (~a ~v)\n" 'current-title (current-title)))
  (begin
    (current-author "Maciej Barć")
    (printf "[DEBUG] (~a ~v)\n" 'current-author (current-author))))

Time hackery in VirtualBox

Maciej Barć — Fri, 07 Jul 2023 22:39:44 UT

Unwanted (VDI) present

Recently I was given a task to run a outdated piece of commercial software on a very outdated (in)famous operating system. Unlucky for me on the given VDI (VirtualBox disk image) the so-called “Guests Additions” that enabled “better” time synchronization were already installed.

Fighting VBox time

So, this is what I had to do to keep the old clock:

turn off networking card in the virtual machine configuration, because we do not want the system to use NTP or other newt service to get the “new” time,
disable getting the host’s clock time: VBoxManage setextradata "WinXP" "VBoxInternal/Devices/VMMDev/0/Config/GetHostTimeDisabled" 1,
and… this magic: VBoxManage modifyvm "WinXP" --biossystemtimeoffset "-341597644449", this thing does the very weird thing of telling the virtual machine BIOS how much to set it back in time, the offset here is total milliseconds between some old date and current date.

Getting the old date

With the Python script snippet below you will get the milliseconds to set back the VirtualBox clock to 01.01.2012 01:00.

from datetime import datetime

round((datetime.strptime("01.01.2012 01:00", "%d.%m.%Y %H:%M")
      - datetime.now()).total_seconds() * 1000)

Comparing objects in Racket

Maciej Barć — Sat, 17 Jun 2023 23:39:38 UT

Equality methods

By implementing a method for equality equal-to? and two extraction methods equal-hash-code-of and equal-secondary-hash-code-of we can define our own object comparison rules.

For more info see Object Equality and Hashing.

Consider the following example:

(define integer%
  (class* object% (equal<%>)
    (super-new)

    (init-field [value 0])

    (define/public (equal-to? other-object recur)
      (= value (get-field value other-object)))

    (define/public (equal-hash-code-of hash-code)
      (hash-code value))

    (define/public (equal-secondary-hash-code-of hash-code)
      (hash-code value))))

If we create a new integer% object we can notice that it is not transparent (we can not inspect values of any of it’s fields).

1 2	(new integer%) ;; => (object:integer% ...)

But if we compare two fresh integer% objects they will be equal.

1 2	(equal? (new integer%) (new integer%)) ;; => #true

Transparent class

A transparent cvlass is a class with the inspect expression valuye se to #false.

From Racket documentation Creating Classes:

Just as for structure types, an inspector controls access to the class’s fields, including private fields, and also affects comparisons using equal?.

Consider the following example:

(define integer%
  (class object%

    (super-new)

    (inspect #false)

    (init-field [value 0])))

If we create a new integer% object we can see it’s field values.

1 2	(new integer%) ;; => (object:integer% 0)

And if we compare two fresh integer% objects they will be equal.

1 2	(equal? (new integer%) (new integer%)) ;; => #true

Moving my Fediverse account to emacs.ch

Maciej Barć — Sat, 17 Jun 2023 22:02:37 UT

I have moved my main Fediverse account from @xgqt@fosstodon.org to @xgqt@emacs.ch.

The new account’s RSS feed can be found at emacs.ch/users/xgqt.rss.

Running nginx under a local user

Maciej Barć — Thu, 18 May 2023 23:17:24 UT

Config

First let’s prepare a suitable nginx configuration file.

This one is pretty bare but it works well for our case:

worker_processes 1;
daemon off;
pid ./nginx/temp/nginx.pid;

error_log /dev/stdout info;

events {
    worker_connections 1024;
}

http {
    client_body_temp_path ./nginx/temp/client 1 2;
    proxy_temp_path ./nginx/temp/proxy;
    fastcgi_temp_path ./nginx/temp/fastcgi;
    uwsgi_temp_path ./nginx/temp/uwsgi;
    scgi_temp_path ./nginx/temp/scgi;

    server {
        listen 127.0.0.1:8080;
        server_name localhost;

        access_log /dev/stdout;
        error_log /dev/stdout info;

        root ./;

        location / {
            autoindex on;
        }
    }
}

Server config is set up for serving all static files from the current directory.

Startup

Preparation

Based on how you want to store _temp_path files it might be necessary to create (or clean up) additional directories, for example:

1 2	rm -r ./nginx/temp mkdir -p ./nginx/temp

Run in current directory

1	nginx -c ./nginx.conf -p ./

BTW, you may want to replace ./ with "$(pwd)" and occurrences in the config with static paths.

Bonus: other simple servers

Some of no-dependency-except-itself http servers it’s good to know about:

Python http.server

1	python3 -m http.server -b 127.0.0.1 8080

Busybox

1	busybox httpd -f -p 127.0.0.1:8080 -v

You can read more about configuring busybox’s httpd on OpenWRT docs.

Bubblewrap cross-architecture chroot

Maciej Barć — Fri, 28 Apr 2023 15:06:33 UT

System preparation

Qemu

Emerge qemu with static-user USE enabled and your wanted architectures.

app-emulation/qemu      QEMU_SOFTMMU_TARGETS: aarch64 arm x86_64
app-emulation/qemu      QEMU_USER_TARGETS: aarch64 arm x86_64

app-emulation/qemu      static-user
dev-libs/glib           static-libs
sys-apps/attr           static-libs
sys-libs/zlib           static-libs
dev-libs/libpcre2       static-libs

OpenRC

Enable qemu-binfmt:

1	rc-update add qemu-binfmt default

Start qemu-binfmt:

1	rc-service qemu-binfmt start

Chrooting

select chroot location (eg /chroots/gentoo-arm64-musl-stable)
unpack the desired rootfs
create needed directories
- mkdir -p /chroots/gentoo-arm64-musl-stable/var/cache/distfiles
execute bwrap
- with last ro-bind mount the qemu emulator binary (eg qemu-aarch64)
- execute the mounted emulator binary giving it a shell program (eg bash)

Chroot with bwrap:

bwrap                                                       \
    --bind /chroots/gentoo-arm64-musl-stable /              \
    --dev /dev                                              \
    --proc /proc                                            \
    --perms 1777 --tmpfs /dev/shm                           \
    --tmpfs /run                                            \
    --ro-bind /etc/resolv.conf /etc/resolv.conf             \
    --bind /var/cache/distfiles /var/cache/distfiles        \
    --ro-bind /usr/bin/qemu-aarch64 /usr/bin/qemu-aarch64   \
    /usr/bin/qemu-aarch64 /bin/bash -l

Libvirt with bridge network

Maciej Barć — Sun, 09 Apr 2023 20:28:38 UT

User-mode

By default you would probably have something like this, the user-mode network:

<interface type="user">
  <mac address="00:00:00:00:00:00"/>
  <model type="virtio"/>
  <address type="pci" domain="0x0000" bus="0x01" slot="0x00" function="0x0"/>
</interface>

Bridge

Bridges can be easily created using the NetworkManager’s TUI tool called nmtui.

Bridge XML configuration for Libvirt

<interface type="bridge">
  <mac address="00:00:00:00:00:00"/>
  <source bridge="br1"/>
  <target dev="vnet2"/>
  <model type="virtio"/>
  <alias name="net0"/>
  <address type="pci" domain="0x0000" bus="0x06" slot="0x00" function="0x0"/>
</interface>

Sysctl options

Be sure the following options are enabled (1):

net.ipv4.ip_forward
net.ipv4.conf.all.send_redirects

and the following options are disabled (0):

net.bridge.bridge-nf-call-iptables

Installing PowerShell modules via Portage

Maciej Barć — Fri, 07 Apr 2023 00:26:43 UT

Building PowerShell

As a part of my work of modernizing the way .NET SDK packages are distributed in Gentoo I delved into packaging a from-source build of PowerShell for Gentoo using the dotnet-pkg eclass.

Packaging pwsh was a little tricky but I got a lot of help from reading the Alpine Linux’s APKBUILD. I had to generate special C# code bindings with ResGen and repackage the PowerShell tarball. Other than this trick, restoring and building PowerShell was pretty straight forward with the NuGet package management support from the dotnet-pkg.eclass.

Alternatively if you do not want to build PowerShell you can install the binary package, I have in plans to keep that package around even after we get the non-binary app-shells/pwsh into the official Gentoo ebuild repository.

Why install modules via Portage?

But why stop on PowerShell when we can also package multiple PS modules?

Installing modules via Portage has many benefits:

better version control,
more control over global install,
no need to enable PS Gallery,
sandboxed builds,
using system .NET runtime.

Merging the modules

PowerShell’s method of finding modules is at follows: check paths from the PSModulePath environment variable for directories containing valid .psd1 files which define the PS modules.

By default pwsh tries to find modules in paths:

user’s modules directory — ~/.local/share/powershell/Modules
system modules directory in /usr/local — /usr/local/share/powershell/Modules
Modules directory inside the pwsh home — for example /usr/share/pwsh-7.3/Modules

Because we do not want to touch either /usr/local nor pwsh home, we embed a special environment variable inside the pwsh launcher script to extend the path where pwsh looks for PS modules. The new module directory is located at /usr/share/GentooPowerShell/Modules.

1 2	dotnet-pkg-utils_append_launchervar \ 'PSModulePath="${PSModulePath}:/usr/share/GentooPowerShell/Modules:"'

So every PowerShell module will install it’s files inside /usr/share/GentooPowerShell/Modules.

To follow PS module location convention we add to that path a segment for the real module name and a segment for module version. This also enables us to have proper multi-slotting because most of the time the modules will not block installing other versions.

Take a look at this example from the app-pwsh/posh-dotnet–1.2.3 ebuild:

src_install() {
    insinto /usr/share/GentooPowerShell/Modules/${PN}/${PV}
    doins ${PN}.psd1 ${PN}.psm1

    einstalldocs
}

And that is it. Some packages do not even need to be compiled, they just need files placed into specific location. But when compilation of C# code is needed we have dotnet-pkg to help.

Binary packages in Gentoo

Maciej Barć — Thu, 23 Mar 2023 08:01:04 UT

Binpkgs generated by user

The binary packages generated by user can have architecture-specific optimizations because they are generated after they were compiled by the host Portage installation.

In addition binpkgs are generated from ebuilds so if there is a USE flag incompatibility on the consumer system then the binpkg will not be installed on the host and Portage will fall back to from-source compilation.

Those binary packages can use two formats: XPAK and GPKG.

XPAK had many issues and is getting superseded by the GPKG format. Beware of upcoming GPKG transition and if you must use XPAKs then you should explicitly enable it in your system’s Portage configuration.

To host a binary package distribution server see the Binary package guide on the Gentoo wiki.

Bin packages in a repository

Binary packages in ::gentoo (the official Gentoo repository) have the -bin suffix.

Those packages might have USE flags but generally they are very limited in case of customizations or code optimizations because they were compiled either by a Gentoo developer or by a given package upstream maintainer (or their CI/CD system).

Those packages land in ::gentoo mostly because it is too hard (or even impossible) to compile them natively by Portage. Most of the time those packages use very complicated build systems or do not play nice with network sandbox like (e.g. Scala-based projects) or use very large frameworks/libraries like (e.g. Electron).

They can also be added to the repository because they are very desirable either by normal users (e.g. www-client/firefox-bin) or for (from-source) package bootstrapping purposes (e.g. dev-java/openjdk-bin). Such packages are sometimes generated from the regular source packages inside ::gentoo and later repackaged.

Ebuild lit tests

Maciej Barć — Thu, 23 Feb 2023 23:00:00 UT

Patching

The file lit.site.cfg has to be inspected for any incorrect calls to executables. For example see src_prepare function form dev-lang/boogie.

Eclasses

Because we will need to specify how many threads should lit run we need to inherit multiprocessing to detect how many parallel jobs the portage config sets.

1	inherit multiprocessing

Dependencies

Ensure that dev-python/lit is in BDEPEND, but also additional packages may be needed, for example dev-python/OutputCheck.

BDEPEND="
    ${RDEPEND}
    test? (
        dev-python/lit
        dev-python/OutputCheck
    )
"

Bad tests

To deal with bad test you can simply remove the files causing the failures.

local -a bad_tests=(
    civl/inductive-sequentialization/BroadcastConsensus.bpl
    civl/inductive-sequentialization/PingPong.bpl
    livevars/bla1.bpl
)
local bad_test
for bad_test in ${bad_tests[@]} ; do
    rm "${S}"/Test/${bad_test} || die
done

Test phase

--threads $(makeopts_jobs) specifies how many parallel tests to run.

--verbose option will show output of failed tests.

Last lit argument specifies where lit should look for lit.site.cfg and tests.

1
2
3

src_test() {
    lit --threads $(makeopts_jobs) --verbose "${S}"/Test || die
}

src_snapshot

Maciej Barć — Thu, 29 Dec 2022 23:00:00 UT

Prototype

Recently while browsing the Alpine git repo I noticed they have a function called snapshot, see: https://git.alpinelinux.org/aports/tree/testing/dart/APKBUILD#n45 I am not 100% sure about how that works but a wild guess is that the developers can run that function to fetch the sources and maybe later upload them to the Alpine repo or some sort of (cloud?) storage.

In Portage there exists a pkg_config function used to run miscellaneous configuration for packages. The only major difference between src_snapshot and that would of course be that users would never run snapshot.

Sandbox

Probably only the network sandbox would have to be lifted out… to fetch the sources of course.

But also a few (at least one?) special directories and variables would be useful.

Ebuild-mode

Maciej Barć — Thu, 29 Dec 2022 23:00:00 UT

Portage

Configure the following for Portage.

1	dev-util/pkgcheck emacs

Emerge

Emerge the following packages:

app-emacs/company-ebuild
dev-util/pkgcheck

Company-Ebuild should pull in app-emacs/ebuild-mode, if that does not happen, then report a bug ;-D

Standard

Add the following to your user's Emacs initialization file. The initialization file is either ~/.emacs.d/init.el or ~/.config/emacs/init.el for newer versions of GNU Emacs.

(require 'ebuild-mode)
(require 'company-ebuild)
(require 'flycheck)
(require 'flycheck-pkgcheck)

(add-hook 'ebuild-mode-hook 'company-ebuild-setup)
(add-hook 'ebuild-mode-hook 'flycheck-mode)
(add-hook 'ebuild-mode-hook 'flycheck-pkgcheck-setup)

Use-Package

We can also configure our environment using a use-package macro that simplifies the setup a little bit.

To use the below configuration the app-emacs/use-package package will have to be installed.

(require 'use-package)

(use-package ebuild-mode
  :defer t
  :mode "\\.\\(ebuild\\|eclass\\)\\'"
  :hook
  ((ebuild-mode . company-ebuild-setup)
   (ebuild-mode . flycheck-mode)
   (ebuild-mode . flycheck-pkgcheck-setup)))

The :defer t and :mode "..." enable deferred loading which theoretically speeds up GNU Emacs initialization time at the cost of running the whole use-package block of ebuild-mode configuration when the :mode condition is met.

Fediverse RSS

Maciej Barć — Tue, 15 Nov 2022 23:00:00 UT

Fosstodon

If you prefer to follow my posts on Fosstodon via RSS, then here is the link: fosstodon.org/users/xgqt.rss.

Chromium

Maciej Barć — Thu, 01 Sep 2022 22:00:00 UT

Dark interface

Force web UI dark mode

1	--enable-features=WebUIDarkMode --force-dark-mode

Hardware acceleration

Accelerated video decoding and GPU support

1	--enable-accelerated-video-decode --enable-gpu

Reader mode

1	--enable-reader-mode

Runtime cache

Use the cache directory /run/user/1000/chrome/cache

1	--disk-cache-dir=${XDG_RUNTIME_DIR}/chrome/cache

Window size

Sawn a window of size 1200x900

1	--window-size=1200,900

Full config

The file /etc/chromium/default is sourced by the Chromium launcher, that's why we can sue bash syntax here.

#!/usr/bin/env bash

# Dark interface
# Force web UI dark mode
CHROMIUM_FLAGS="${CHROMIUM_FLAGS} --enable-features=WebUIDarkMode --force-dark-mode"

# Hardware acceleration
# Accelerated video decoding and GPU support
CHROMIUM_FLAGS="${CHROMIUM_FLAGS} --enable-accelerated-video-decode --enable-gpu"

# Reader mode
CHROMIUM_FLAGS="${CHROMIUM_FLAGS} --enable-reader-mode"

# Runtime cache
# Use the cache directory /run/user/1000/chrome/cache
CHROMIUM_FLAGS="${CHROMIUM_FLAGS} --disk-cache-dir=${XDG_RUNTIME_DIR}/chrome/cache"

# Window size
# Sawn a window of size 1200x900
CHROMIUM_FLAGS="${CHROMIUM_FLAGS} --window-size=1200,900"

Binary

If you use www-client/chromium-bin, then the config is located at /etc/chromium/default and CHROMIUM_FLAGS is CHROMIUM_BIN_FLAGS.

KDE Emacs

Maciej Barć — Thu, 25 Aug 2022 22:00:00 UT

Proper window size

Sometimes while the Emacs GUI window is tiled to a side or maximized small gaps may appear around the window. This "bug" can be worked around by:

right-click on the title bar,
"More Actions",
"Configure Special Window Settings…",
"Add Property",
"Obey Geometry Restrictions",
Select "Force" form the combo box,
Select "No" from the radio buttons.

Opening files from Dolphin in one Emacs instance

Emacs daemon can help with that. But before you run emacs --daemon, I need You to know that there might be a better way:

1 2	(unless (or noninteractive (server-running-p)) (server-start))

Adding the above to Your Emacs config will cause Emacs to start a daemon after it is opened (and no other Emacs servers are running), this also does not require --daemon flag.

After the daemon is started You can open files by right-clicking on them and selecting to open them in "Emacsclient".

Furthermore: You also utilize --iconic and add emacs --iconic to your Plasma startup. This is way better than using emacs --daemon because you can just click on your taskbar to open the minimized Emacs window. Also, Emacs will load all Your graphical libraries and configurations so Your theme will look properly and not as if Emacs was being used on the console.

Breeze theme

Sadly I have not found any theme that would look like Plasma. I use the spacemacs theme which looks a little bit similar, especially the background color comes close to Breeze's dark background color.

Note that the theme which You load with the function load-theme is a different thing that the GTK theme Emacs uses.

The GTK theme should be enabled if Your Emacs version is built with GTK support. On Gentoo this setting is controlled with the gtk USE flag. Also the flag toolkit-scroll-bars can be enabled for a look of scroll-bars consistent with the selected toolkit.

Xresources

There is a different approach to theming Your Emacs that loading a theme defined in ELisp - You can use a ~/.Xresource file.

If you do not load any theme in your configuration Emacs will by default read the .Xresources file, unless the --no-x-resources flag is used.

Here are a few Xresources config files that come close to the default Breeze theme:

Dbus integration

Emacs can be built with FreeDesktop's D-Bus support to communicate over the dbus protocol. This can come handy when using ERC as it has a setting to enable desktop notifications on mentions (erc-desktop-notifications.el).

The dbus interface can also be utilized to query desktop-oriented daemons, for example this library talks to the Bluetooth daemon.

KDE development

Those are some ELisp libraries that I found while browsing GitHub, they might be useful for somebody who delves into KDE app development.

Opening files in different applications

In addition to async-shell-command and start-process-shell-command I wrote this small library that may come handy.

Outside Emacs, inside Plasma

Sadly the KDE team did not add support to emulate Emacs-like keys in Plasma itself, but some applications like, for example Kate have configuration options to customize the key bindings. This is a repository explaining how to setup Kate's bindings.

Pkgcheck-Flycheck

Maciej Barć — Fri, 05 Aug 2022 22:00:00 UT

News

Repository

With this commit first GNU Emacs integration was merged into the pkgcheck repository.

History

Thanks

Huge thanks to Sam James and Arthur Zamarin for support and interest in getting this feature done.

Installation

Unmasking

The Flycheck integration is unreleased as of now, this will (hopefully) change in the future, but for now You need live versions of snakeoil, pkgcore and pkgcheck.

File: /etc/portage/package.accept_keywords/pkgcore.conf

1
2
3

dev-python/snakeoil  **
sys-apps/pkgcore     **
dev-util/pkgcheck    **

Also You will need to unmask app-emacs/flycheck and its dependencies.

File: /etc/portage/package.accept_keywords/emacs.conf

1
2
3

app-emacs/epl
app-emacs/pkg-info
app-emacs/flycheck

Emerging

Install pkgcheck with the emacs USE flag enabled.

File: /etc/portage/package.use/pkgcore.conf

1	dev-util/pkgcheck emacs

Afterwards run:

1 2	emerge -1av dev-python/snakeoil sys-apps/pkgcore dev-util/pkgcheck emerge -av --noreplace dev-util/pkgcheck

Configuration

Following is what I would suggest to put into your Emacs config file:

(require 'ebuild-mode)
(require 'flycheck)
(require 'flycheck-pkgcheck)

(setq flycheck-pkgcheck-enable t)

(add-hook 'ebuild-mode-hook 'flycheck-mode)
(add-hook 'ebuild-mode-hook 'flycheck-pkgcheck-setup)

If You are using use-package:

(use-package flycheck
  :ensure nil)

(use-package ebuild-mode
  :ensure nil
  :hook ((ebuild-mode . flycheck-mode)))

(use-package flycheck-pkgcheck
  :ensure nil
  :custom ((flycheck-pkgcheck-enable t))
  :hook ((ebuild-mode . flycheck-pkgcheck-setup)))

The lines with :ensure nil are there to prevent use-package from trying to download the particular package from Elpa (because we use system packages for this configuration).

Mkdocs with Scribble

Maciej Barć — Mon, 11 Jul 2022 22:00:00 UT

Intro

Instead of changing CSS style for Your Racket projects documentation, You may be interested in compiling Markdown files generated form Scribble source into HTML documentation website.

Creating MkDocs project

Create docs directory and mkdocs.yml config file in current directory, along with a dummy index.md file in docs folder.
1

mkdocs new .
Edit the name of the project.

Replace Racket-Project with your project name.
1 2

--- site_name: Racket-Project

Building Scribble

Generate markdown files form scribble documentation.

Replace Racket-Project.scrbl with path to your scribble documentation main source file.

1	scribble --markdown --dest ./docs --dest-name index.md Racket-Project.scrbl

Building Markdown

Compile HTML documentation from the markdown source.

1	mkdocs build

HTML files should appear in the site directory.

Running the server

Some features, like search for example are only available when running the mkdocs server.

1	mkdocs serve

Caveats

Some scribble functions do not look good or work correctly for markdown-to-HTML compilation by MkDocs.

table-of-contents - looks like a source block
index-section - letter links do not work

Example configuration

site_name: Racket-Ebuild
site_author: xgqt@riseup.net
site_description: library to ease ebuild creation
site_url: https://gitlab.com/gentoo-racket/racket-ebuild

repo_name: gentoo-racket/racket-ebuild
repo_url: https://gitlab.com/gentoo-racket/racket-ebuild

plugins:
  - search

theme:
  name: material

extra:
  social:
    - icon: fontawesome/brands/gitlab
      link: https://gitlab.com/gentoo-racket/racket-ebuild

Lenovo 81nc advanced bios options

Maciej Barć — Sun, 24 Apr 2022 22:00:00 UT

Preparation

First using a needle or a toothpick click a button on the right side of the laptop (indicated by a bent arrow), this will start the machine up in BIOS selection menu where you choose the BIOS setup option.

Then, in the BIOS menu disable option to check laptop charge level while it is shut down. If not disabled it will interfere with key combination that has to be pressed while laptop is shut down. This can be turned back after the advanced BIOS menu is enabled.

After that "Exit saving changes" and shutdown.

Keys

I thought it was a joke at first but it really is true that a special combination of keys has to be pressed depending on the laptop model (while it is shut down).

For my laptop it is as follows:

1
2
3

F4 4 r f v
F5 5 t g b
F6 6 y h n

References

systemd-custom-unit

Maciej Barć — Thu, 07 Apr 2022 22:00:00 UT

Template

File: /etc/systemd/system/APP.service

[Unit]
Description=Run APP application

[Service]
Type=simple
ExecStart=/usr/bin/LANG APP_DIR/APP APP_ARGS
Restart=on-failure
User=root
WorkingDirectory=APP_DIR

[Install]
WantedBy=multi-user.target

Also, the application might need to reference a PID file, let systemD know abut it via PIDFile.

1	PIDFile=/tmp/APP.pid

Example

File: /etc/systemd/system/julia_dash_app.service

[Unit]
Description=Run Julia Dash application

[Service]
Type=simple
ExecStart=/usr/bin/julia /root/julia_dash_app/main.jl
Restart=on-failure
User=root
WorkingDirectory=/root/julia_dash_app

[Install]
WantedBy=multi-user.target

Portage CI

Maciej Barć — Mon, 07 Mar 2022 23:00:00 UT

Potential benefits

Running tests

test BEFORE (src_test) and AFTER (pkg_postinst) installation
test if and how services break if they are not reloaded
test buildsystem configuration
sandbox enforces strict and consistent build rules
benchmarking with different compilation flags and libraries versions/releases

Configuration matrix

We can test across Cartesian product of different configuration settings, like:

USE flags
MAKEOPTS
CFLAGS, CXXFLAGS, CPPFLAGS, LDFAGS, RUSTFLAGS, etc.
arches (cross-compilation or run in qemu)
static linking
supported releases & versions of libraries (eg. glibc & musl)

Also, we could create diffs of installed files across different merges.

Reproducibility

mini overlay with ::gentoo or any other (eg. company's own) as master
record VCS (eg. git) hash of the dependent overlays

Binaries

grab dependencies from binhosts
distribute built binaries (maybe upload to a company's own artifacts server)
make AppImages

Getting there

How do we run this?

Do we want to write a proper tool, which we probably do or do we just run Portage + shells scripts?

Do we want to run under root, user, in eprefix, maybe all in docker?

Configuration files

The .portci directory contains the configuration.

Bug 799626

Link: bugs.gentoo.org/799626

Instead of using Ansible, Python, Yaml or Scheme we might use something similar to this for simple configuration, or if gets merged to upstream Portage the better.

Worth mentioning is the idea from Michał Górny who proposes to configure portage with toml files, like the example given in the bug report.

[package.unmask]
~virtual/libcrypt-2

[package.use.mask]
sys-libs/libxcrypt -system -split-usr

[package.use.force]
sys-libs/glibc -crypt

Also, package.x + Toml == a match made in heaven, it looks very nice!

Make gallery-dl work like youtube-dl

Maciej Barć — Sat, 25 Sep 2021 22:00:00 UT

Make gallery-dl work like youtube-dl

A configuration file to download everything into current directory, like yotube-dl does.

File: ~/.config/gallery-dl/config.json

{
  "directory": [],
  "base-directory": "./"
}

Portage

Maciej Barć — Sat, 25 Sep 2021 22:00:00 UT

Switching from a git repository hosting

For nearly 2 years I have been synchronizing settings between my Gentoo machines via a git repository that is installed system-wide via portage itself.

This actually gets a little tiresome and slow as the package that installs the configuration has to be re-installed each time we want to update the settings.

So I thought it could be cool if I can just push files around between my machines with one command. Now: we can use rsync or scp but /etc/portage is owned by root so we either have to change the permissions to a user we use to ssh or a group that user is in.

Portage users

First change portage permissions of /etc/portage, now all users in the portage group will be able to modify the configuration

1 2	chown -R root:portage /etc/portage chmod -R g+w /etc/portage

Synchronizing

We can do a rsync from different machine with:

1	rsync -r /etc/portage REMOTEHOST:/etc --exclude=".git" --exclude="make.profile" --copy-unsafe-links

Reminder that this can also be done as a cron job!

Portage snapshots with git

Probably the best thing I got out of genlica is that I engineered a script to automatically do a git commit of the changes to the portage configuration.

Emerge git

1	emerge --noreplace --verbose dev-vcs/git

Copy the file that does the snapshots

1 2	mkdir -p /etc/portage/postsync.d curl -o /etc/portage/postsync.d/99-degitmerge.sh "https://gitlab.com/xgqt/genlica/-/raw/master/portage/postsync.d/99-degitmerge.sh"

HTML Renderers

Maciej Barć — Mon, 03 May 2021 22:00:00 UT

How it should be?

I imagine that a web browser should have been a "window" to the Internet world that provides easy and efficient way to graphically access resources exposed by multiple protocols: HTTP(S), (S)FTP, Gopher, Gemini, etc…

How it is?

Only few protocols are supported!

Recently FTP support got "deprecated" in Firefox. It can still be enabled in by setting network.ftp.enabled to true. FTP support is announced to be completely gone in FF 90. Chrome dropped FTP some time ago. # BUT! Luckily we have Emacs! GNU Emacs has packages to support all kinds of protocols. - eww which is a simple HTTP(S) browser like w3m (also renders images) - tramp allows you to access files by SSH - elpher allows you to access Gemini and Gopher sites (graphically) - ange-ftp allows you to connect to FTP servers - and finally net-utils which wraps around system utilities to provide interactive mode for many protocols, ie.: gopher, irc, ntp, pop3, www

Awesome Racket language features

Maciej Barć — Sun, 02 May 2021 22:00:00 UT

Also see: Fast-Racket at Racket's GitHub Wiki

Creating binaries

You can create portable binaries with Racket's raco command! Use raco exe and raco distribute.

More -> https://docs.racket-lang.org/raco/exe.html

Sample games

Racket provides a executable plt-games, when ran (from console) it opens a menu of miscellaneous games, among them: jewel, minesweeper, aces, spider, checkers. & more (20 games total).

Plots

You can plot data in 2d & 3d forms.

2D

Sample code:

#lang racket/base
(require racket/gui/base racket/math plot)

(plot-new-window? #true)

(plot (function sin (- pi) pi #:label "y = sin(x)"))

3D

Sample code:

#lang racket/base
(require racket/gui/base racket/math plot)

(plot-new-window? #true)

(plot3d
 (surface3d (lambda (x y) (* (cos x) (sin y)))
            (- pi) pi (- pi) pi)
 #:title "An R × R → R function"
 #:x-label "x" #:y-label "y" #:z-label "cos(x) sin(y)")

Browser

There's a included library to render web pages, just "(require browser)".

Sample code:

#lang racket
(require browser)

(open-url "https://xgqt.gitlab.io/")

FFI

You can use Racket's Foreign Function Interface to interact with non-Racket libraries to make use of very fast libraries written in (mainly) FORTRAN & C.

For example sci uses FFI for CBLAS & LAPACK.

Parallelism

For greater speed up with parallel execution there are futures, places and distributed places (for distributed programming).

Sage Math on Gentoo

Maciej Barć — Mon, 22 Mar 2021 23:00:00 UT

Intro

Sage may be available on your distro but on Gentoo such frivolities for students are not there yet, so I had to install it the manual way.

User

I went to the Sage website, to the "download-source" link. The source mirror I picked was France.

Ok, so let's follow Sage Math build instructions and get it going

wget www-ftp.lip6.fr/pub/math/sagemath/src/sage-9.2.tar.gz
tar xvf sage-9.2.tar.gz
cd sage-9.2
./configure
make

And now, let's wait…

Portage

After a long, long, long time waiting I remembered that there existed a Gentoo overlay for Sage. And in the meantime I thought I'd try that solution instead since some good Gentoo people already did most of the effort.

Just a few files to edit…

File: /etc/portage/repos.conf/sage-on-gentoo.conf

# -*- conf -*-


[sage-on-gentoo]

auto-sync = yes
location = /var/db/repos/sage-on-gentoo
priority = 999
sync-git-clone-extra-opts = --depth=999999999 --no-shallow-submodules --verbose
sync-git-pull-extra-opts = --verbose
sync-type = git
sync-umask = 022
sync-uri = https://github.com/cschwan/sage-on-gentoo.git
sync-user = root:portage

File: /etc/portage/package.accept~keywords~/zz-sage

# -*- conf -*-


sci-mathematics/sage                    **

*/*::sage-on-gentoo

dev-python/cvxopt

media-gfx/tachyon

sci-libs/bliss
sci-libs/dsdp
sci-libs/fflas-ffpack
sci-libs/fplll
sci-libs/libhomfly
sci-libs/linbox
sci-libs/m4rie

sci-mathematics/glpk

File: /etc/portage/package.use/zz-sage

# -*- conf -*-


sci-mathematics/sage                    -doc-html -doc-html-bin
sci-mathematics/sage                    -doc-pdf -doc-pdf-bin
sci-mathematics/sage                    -jmol
sci-mathematics/sage                    X bliss meataxe

dev-python/pplpy                        doc

sci-libs/cddlib                         tools
sci-libs/pynac                          -giac

sci-mathematics/eclib                   flint
sci-mathematics/flint                   ntl
sci-mathematics/glpk                    gmp
sci-mathematics/gmp-ecm                 -openmp
sci-mathematics/lcalc                   pari
sci-mathematics/maxima                  ecls
sci-mathematics/pari                    gmp doc

Now - let's build Sage with Portage!

>>> Emerging (1 of 100) sci-mathematics/cliquer–1.21::gentoo

At least I know more or less how long I'm going to wait and know what exactly fails to build, if anything does.

Final

Build

$ qlop -tv sage

> 2021–03–23T20:49:12 >>> sci-mathematics/sage–9999: 55′04″

Git stats

Overlays

This info we can easily gather with executing:

1	emerge --info

Gentoo' HEAD: 33f2d770c28307b1e9a1199c681e1c543602c6d4

Sage-on-Gentoo's HEAD: f7eac5b7e1a844132164b7593dab85cd87918664

Sage

Sage repository's HEAD (because we are using the live (9999) ebuild):

1	cat /var/cache/distfiles/git3-src/sagemath_sage.git/refs/heads/develop

Which returns: 5cb72aade9b297c10bb0f1ae8529466e5b5eb41d

MTG alter-art collection

Maciej Barć — Thu, 14 Jan 2021 23:00:00 UT

Story

In 2013–2017 I was very interested in Trading card game “Magic: the Gathering”. I started playing during the release of Theros and quit somewhere during Shadows over Innistrad. I still keep a small collection of alternative artwork that I have painted on the cards.

Binder

Those are pages from the binder I store the card in. Also a lone “Obsession” resource card from The Spoils.

Cards

This list is sorted by the time I created the alter-art. I do this from memory so it’s probably not accurate.

Swamp v1
- spider over card, the first alter I’ve made
Swamp v2
- re-imagining of Urborg, Tomb of Yawgmoth
Force Spike v1
- extended cape, head explosion
Lava Axe
- inspired by Football game from the Room
Force Spike v1
- blood fountain from head
Forest v1
- rose
Balustrade Spy
- inspired by Romeo & Juliet
Duress v1
- inspired by the Passion of Jesus Christ
Gray Merchant of Asphodel
- re-imagination as Zombie servant
Sign in Blood
- Yawgmoth’s Bargain pastiche
Unsummon
- extended art
Assassinate
- inspired by Time Spiral block block style, e.g. Yixlid Jailer
Worst Fears
- inspired by Terror
Duress v2
- extended art
Duress v3
- inspired by Brainstorm
Swamp v3
- Mox Jet pastiche
Forest v2
- Mox Emerald pastiche
Plains
- Mox Pearl pastiche
Negate
- extended art, melting person
Consume Spirit
- extended art
Merciless Resolve
- extended art with sharpie
Duress v4
- inspired by Gitaxian Probe, the last alter I’ve made

Mastodon

Maciej Barć — Wed, 13 Jan 2021 23:00:00 UT

I has decentralization

So, yea, I’m on Fosstodon. https://fosstodon.org/@xgqt

Hope I don’t get banned ;^)

But in all seriousness, it’s been pretty great. My colleagues warned me that there’s a lot of SJWs but only one person I spoke with wanted to be addressed “differently” + didn’t express that aggressively, so whatever.

Se yall on mastodon ;D

How to read this blog

Maciej Barć — Fri, 01 Jan 2021 23:00:00 UT

Git

Because contents of this blog are stored in a git repository you can just

1	git clone --verbose --recursive https://gitlab.com/xgqt/blog

then, read the "raw" ORG files in 'posts' directory or make the HTML version executing the 'dev.sh' script (remember that you will need GNU Emacs to render the posts into HTML files).

Then, you can just git pull to read the news whenever you wish, maybe do it with cron or a script that will pull many repos at once, for example with this script.

RSS

Org-Static-Blog creates a RSS Feed file rss.xml, so to subscribe add the link https://xgqt.gitlab.io/blog/rss.xml to your favorite RSS reader.

You can also subscribe to the GitLab repository Atom feed.

EmojiD

Maciej Barć — Sun, 20 Dec 2020 23:00:00 UT

Short story long

We were discussing some vulnerabilities on the src~prepare~ group's [matrix] channel and when we're talking about systemd errors. I just felt like opening their GitHub and browsing the code. I was just reading the comments… and I saw a comment about kernel APIs and there a emoji. My feeling is probably best expressed my common "KEK". I chuckled. The "Abstract" in 0.0.1 is the original idea I typed on [matrix]. The funniest part of this "development" for me is probably that Emacs on my system doesn't display properly ANY of the emojis in emojid. I had to go back and forth between the source and log files opened in FF (because it renders the emojis properly), emojipedia and "broken" Emacs.

0.0.1 "😃 ️ 🌍 🍞 🚗 📞 🎉 ♥️ 🏁"

What you do is clone the repository, execute make and run the binary. Read your log and see if your system is "affected" :P.

👋

And remember emoticons made of the symbols found on the keyboard will always look better ;)

2020 recap

Maciej Barć — Thu, 17 Dec 2020 23:00:00 UT

Recap

What I did this year:

began studying at WSIiZ
drank a lot of alcohol with friends
installed NetBSD ;)
learned Nginx and Ansible
recruited new people to the src_prepare group
struck a nerve with some commies
took maintainership of gallery-dl and PPSSPP
tweaked my configs
went back to KDE and Firefox (missed them)
worked with Zigbee (probably not doing that again)

Wishes

What do you wish in new year?

I wish you all merry Christmas and happy new year. Less bugs, more resolved issues, no wontfixes, better compatibility. Faster compilation, less failures. And of course no lawsuits, no copyright infringements and better government.

Portage system replication

Maciej Barć — Fri, 13 Nov 2020 23:00:00 UT

Intro

Backing up using this method takes a lot less space - ~60MB (without distfiles) and can be restored on almost any system (running portage) and tweaked afterwards for, say, CPU architecture. I've created a a short script with similar method in here.

What we need

ebuild repositories are installed with git
distfiles (those might be gone when we want to replicate)

Backup

# System info
emerge --info > info.txt

# Portage tree
cp -Lr /etc/portage .

# Portage layout
tree -a -L 2 /etc/portage > layout.txt

# Packages in @world
cp /var/lib/portage/world .

# Installed sets
cp /var/lib/portage/world_sets .

# Installed packages (with versions)
qlist --installed --nocolor --umap > qlist-use.txt
qlist --installed --nocolor --verbose > qlist-ver.txt

# Distfiles
cp -rv "$(portageq envvar DISTDIR)" distfiles

# Ebuild database
cp -r /var/db/pkg pkgdb

Restoration

To faithfully restore the system perform those actions as root

# Copy the portage tree to /etc
rm -dr /etc/portage
cp -r portage /etc/portage

# Checkout the gentoo repo to a commit specified in info.txt
cd "$(portageq get_repo_path / gentoo)"
git checkout # <commit ID>

# Copy distfiles
cp -r distfiles/* "$(portageq envvar DISTDIR)"/

# Fake-install @world and sets
cp world /var/lib/portage/world
cp world_sets /var/lib/portage/world_sets

# Emerge the exact packages from qlist-ver.txt
emerge --keep-going=y -1Oav $(sed 's/^/=/' qlist-ver.txt)

Old Access Point

Maciej Barć — Tue, 01 Sep 2020 22:00:00 UT

Introduction

On some old routers, namely TP-Link's TL-WR840N version 2, there may not be a option to switch to access point mode. This is what you have to do to access that mode indirectly.

Steps

Power off the router
Unplug RJ cable from the WAN port
Connect the router to a PC (using one of the LAN ports)
Power on the router
Log it to the web console entering your router's IP, you can find out the IP by executing ip --color a (on a Linux box) if the router's DHCP server is still active
In LAN settings give your router a static client IP that fits into a network you want to connect it to; example: 192.168.100.100/24 (make sure no other hosts are associated with that IP in the target network)
Restart the router
Log in to the web console entering the IP you have set
Turn off the DHCP server (DHCP -> DHCP Settings -> DHCP Server: Disable & Save)
Power off the router
Plug the cable from a network you want the router connected to to one of the LAN ports
Power on the router
Log in to the web console entering the IP you have set
Turn on the wireless network and set it up (SSID, password, etc.)
Done! :D

Sources

Internet EU

Maciej Barć — Sat, 04 Jul 2020 22:00:00 UT

I think this is quite important and wanted to share it.
YouTube link: https://www.youtube.com/watch?v=WdwegN7u6x8
Invidio link: https://invidio.us/watch?v=WdwegN7u6x8

Polish original

Internet stał się tym czym jest, stał się takim światem w miniaturze dzięki dobrowolnemu zaangażowaniu zwykłych ludzi, dzięki brakowi regulacji. I to was boli, bo rozwój internatu jest przykładem tego, jak mógłby się rozwijać nasz świat, gdyby nie te wszystkie wasze regulacje, gdyby nie ten ciężki plecak przepisów i podatków który każdy z nas musi na co dzień dźwigać. Internet to jest po prostu ostatni bastion wolności i to wam nie daje spać, bo to jest dowód na to, że wszystkie wasze regulacje i te rozporządzenia, dyrektywy, są tak naprawdę zbędne i szkodliwe i świat bez tego rozwijałby się lepiej, rozwijałby się dokładnie tak jak Internet, że gdyby nie te wasze właśnie ambitne plany, wartości dodane, efekty dźwigni, wysyłanie silnych sygnałów, to wszystko, żyłoby się nam po prostu lepiej i prościej. Dlatego próbujecie to zniszczyć, dlatego próbujecie wsadzić stopę w drzwi za każdym razem kiedy pojawia się okazja. Ale my nie chcemy waszej nogi w tych drzwiach. Teraz cofacie się o parę centymetrów, bo ludzie protestują, ale my nie chcemy was tam w ogóle, nie chcemy waszych regulacji, nie chcemy waszych łap w Internacie. To działa dobrze, twórczość rozwija się w Internecie bez żadnych waszych regulacji.

English translation

Interent has become what it is, it has become a miniature world due to the voluntary involvement of ordinary people, thanks to the lack of regulation. And this hurts you, because the development of the Intenet is an example of how our world could develop, without all your regulations, without this heavy backpack of regulations and taxes that each of us must carry on a daily basis. The internet is simply the last bastion of freedom and this is the thing that doesn't let you sleep, because it is proof that all your regulations and those ordinances, directives, they are really unnecessary and harmful and the world would develop better without it, it would develop exactly like the Internet, that if it weren't for your ambitious plans, added values, leverage effects, sending strong signals, then everyone would have lived just better and simpler. That's why you try to destroy it, that's why you try to stick your foot in the door whenever there is an opportunity. But we don't want your leg in our door. Now you are retreating a few centimeters because people are protesting, but we don't want you there at all, we don't want your regulations, we don’t want your hands in the Internet. It works well, creativity develops on the Internet without any of your regulations.

waterfox

Maciej Barć — Sun, 24 May 2020 22:00:00 UT

Time in Firefox

I love Firefox, it's reasonably secure, private, customizable, and most importantly it's different. In the world of Google's reign this is a big plus. You can be sure that the one spying on you will be at most Mozilla "anonymous data collection" ;P Recently with upgrade to version 68.8.0 I have experienced weird image artifacts: some favicons on tabs were replaced with white squares and random images would have artifacts on them. The whole YouTube website had pink & green distorted thumbnails. I have experienced this behavior on my T440 Thinkpad (Intel GPU) laptop and my desktop with Nvidia. I had posted this under a bug report of another user who experienced weird behavior on some websites with the 68.8.0 version of Firefox here. With update to 76.0.1 I was logged off from all the websites and my stylus themes got deleted (luckily i had a backup). The 76.0.1 searchabr is absolutely hideous, it feels like something made for a Windows tablet. The artifacts still remained on 76.0.1. So i decided to give Waterfox a shot.

Experience part 0

Lest talk about pre-experience; keep in mind that this is really not a good comparison. Waterfox in not available in the main gentoo repository, but using "eix -R Waterfox" I was able to find it in the poly-c overlay (overlays are similar to AUR in Arch). The only hiccup i had during compilation was to be expected. There is a problem with the "-fno-common" flag being turned on by default in GCC 10, so for some builds you have to turn "-fcommon" on. Other than that the compilation went smoothly, it took 37 minutes 43 seconds on first run which is ridiculous compared to Firefox which takes approximately 1 hour on my 4-core development machine.

Spyware?

I only want you to think of Chrome or Chromium - they are produced by the biggest advertising company in the world. So yes, Waterfox seems like a lesser evil, but you can always dive in <about:config> and block any or all malicious connections with /etc/hosts and packet filters (yes i know this is not ideal). Lets confront some statements on spyware watchdog

Waterfox connects to spyware services when it is first run

Same as Firefox. It may not do that if you import your own profile (haven't tested that though).

Waterfox has a communication problem

I wanted to read the "policy" - link doesn't work - https://www.waterfox.net/en-US/privacy/waterfox/ Contents of the linked webpage:

1	<?xml version="1.0"?><updates></updates>

Cool.

Waterfox "phones home" with information about your computer whenever you start it up

Quoting: "According to its privacy policy, Waterfox collects the following information by default:" "by default" is a important wording here.

Waterfox offers spyware search engines to its users and uses Bing as its default search engine

That is literally the first change I do on my browsers.

Waterfox sends all website notifications through Mozilla's servers

So does Firefox…

Waterfox is integrated into the "Firefox Accounts" spyware platform

You don't have to use it. With Waterfox I stopped to.

Waterfox is self updating software

It is not as much as Discord is. Discord as a example will refuse to connect to the server if its version is too low. You can still run outdated Waterfox if you wish to. Also those updates will be disabled if you use the ebuilds. This is mostly used only on Windows… and if you use your Windows you probably know what you signed up for.

So what?

I do not question the legitimacy of Spyware Watchdog's statements. I just compare them with my own habits and thoughts. For me Waterfox == Firefox spyware level. Keep in mind that Firefox introduced more questionable integrated services in new releases.

Small things that make me happy

I was very impressed to find some cool features in Waterfox:

it's menu is compatible "global menu" on KDE Plasma - i was very surprised by this; this thing is mostly sound on chromium-based applications (the damned electron) and QT applications
better theming - Waterfox uses the old Firefox theme by default with "smooth" tabs
most addons just work - uBlock Origin, Decentraleyes, Plasma Integration, Smart HTTPS, SpanTree - GitLab Tree and Stylus work fine
it's Firefox as you knew it; I missed the good old Firefox ;)
back-ported security settings - container tabs work!

Is this worth it?

Absolutely. In my opinion Waterfox is a great browser that I can live in. Maybe consider giving Waterfox a shot if you are not as much into security as Spyware Watchdog people are and want reasonable compromise.

Sources

systemd

Maciej Barć — Fri, 22 May 2020 22:00:00 UT

Init basic functions

Init should:

be the first started process - PID 1
continue running until the system is shut down

Why systemd is more than init

Full system management

systemd needs to run as PID 1 to parenthood other services and… other parts of itself (listed below).

systemd absorbed

cron -> timers
seat tracker -> systemd-logind
service manager -> systemd-systemctl
udev -> systemd-udevd
system logger -> systemd-journald
network manager -> systemd-networkd
bootloader -> systemd-boot
hostname -> systemd-hostnamed
chroot -> systemd-nspawn
resolv.conf generator -> systemd-resolved

Additionally systemd is also

QR code generator
http server (cockpit)
home manager -> systemd-homed
tmp manager -> systemd-tmpfiles

Why it's bad

systemd growth to cover more and more of other services capabilities is dangerous. It can mean that if we find a exploit in one part of systemd it will be easy to compromise the whole system. Actually, there is a even bigger problem - most of the time a user would like to run a standalone service covering one of the uses already covered by systemd - like cronie or rsyslog.

But what about cgroups

Cgroups are nothing new, they are available in other service managers too. Check out cgroups in OpenRC.

Alternatives

OpenRC

Primarily used by Gentoo based systems. Was adopted to Devuan and Artix. Alpine Linux uses it probably because it started out as a Gentoo-based system. Is also available in Debian - though that will still use some systemd services, notably systemd-udevd.

Runit

Available in Void Linux - the recommended init for that system.

Pure System V init

Most popular use of this is found in old CentOS, Slackware, Antix and MX Linux.

S6

Check out Devuan if you want to dive into this topic.

systemd + Emacs

One could think that because systemd and Emacs cover a lot of things - systemd - system management and emacs - user utilities - a fusion of two would be very good and will lack so-called bloat. There is one "problem" however - Emacs can be used also as a init! And that doesn't necessarily mean a lot more code being added. So i guess Emacs + Linux (kernel) is the way to go ;P

Was systemd a inside job?

Probably not - Microsoft made their own init for Azure because… systemd was to big… systemd is a history of what happens when everybody wants to be like the rest - adoption of systemd.

Is systemd the new busybox?

This is an interesting concept. There is one bad thing however - you can compile bysybox with any of its utilities and it will work - you can't do that with systemd, you will have to modify and fork it - like eudev and elogind projects

OpenRC prejudice

Many people think of OpenRC as a old SysVinit. I encourage you to check it out and see that most stuff you probably do with systemd you can get from OpenRC (service manager) + cronie (cron/timers) + htop/pstree (full description of system as opposed to "systemctl status")

Basic OpenRC vs systemd commands

OpenRC systemd ————————— ————————— rc-status -a systemctl status rc-service SERVICE start systemctl start SERVICE rc-service SERVICE stop systemctl stop SERVICE rc-update add SERVICE systemctl enable SERVICE rc-update del SERVICE systemctl disable SERVICE