Config

First let’s prepare a suitable nginx configuration file.

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

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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:

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

Run in current directory

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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

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python3 -m http.server -b 127.0.0.1 8080

Busybox

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busybox httpd -f -p 127.0.0.1:8080 -v

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

System preparation

Qemu

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

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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:

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rc-update add qemu-binfmt default

Start qemu-binfmt:

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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:

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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

User-mode

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

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<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

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<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

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.

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inherit multiprocessing

Dependencies

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

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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.

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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.

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

Portage

Configure the following for Portage.

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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.

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(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.

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(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.

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:

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(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:

• https://github.com/kuriot/xresources-breeze-theme/blob/master/.Xresources
• https://gitcode.net/mirrors/mbadolato/iTerm2-Color-Schemes/-/blob/master/Xresources/Breeze

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.

News

Repository

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

History

• https://github.com/pkgcore/pkgcheck/issues/417
• https://github.com/pkgcore/pkgcheck/pull/420
• https://github.com/gentoo/gentoo/pull/26700

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

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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

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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

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dev-util/pkgcheck    emacs

Afterwards run:

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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:

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(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:

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(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).