rnhmjoj 9be0529210 nixos/console: fix console setting reloading ... It's a dull and boring day, it's cold outside and I'm stuck at home: let me tell you the story of systemd-vconsole-setup. In the beginnings of NixOS[1], systemd-vconsole-setup was a powerful sysinit.target unit, installed and running at boot to set up fonts keyboard layouts and even colors of the virtual consoles. If needed, the service would also be restarted after a configuration change, consoles were happy and everything was good, well, almost. Since the service had no way to specify the dependency "ttys are ready", modesetting could sometimes happen *after* systemd-vconsole-setup had started, leaving the console in a broken state. So abbradar worked around that by putting a systemd-udev-settle `After=`. In the meanwhile, probably realizing their mistake, systemd added a shiny udev rule to start the systemd-udev-settle at the right time[2]. However, the rule bypassed systemd by directly running the binary `systemd-udev-settle`, and the service - though still installed - fell into disuse. Two years would pass before a good samaritan, seeing the poor jobless systemd-udev-settle service, decided to give it the coup de grâs[3] by unlisting it from the installed units. This, combined with another bug, caused quite a commotion[4] in NixOS; to see why remember the fact that `WantedBy=` in upstream units doesn't work[5], so it had to be added manually in cc542110, but while systemd removed it, the NixOS unit continued to install and restart the service, making a lot of fuss when switching configuration. After at least thee different tentative fixes, deedrah realised[6] what the root cause was and fpletz put the final nail[7] in the coffin of systemd-udev-settle. The service would never see the light of a boot again, NixOS would not restart it all the time but thanks to udev consoles would still get their pretty fonts and playful colors. The En.. ..no, wait! You should ask what came of systemd-udev-settle, first. And why is the service even around if udev is doing all the work? Udev-settle, like the deceitful snake that he is, laid hidden for years. He looks innocuous doesn't it? A little hack. Only until it leaves his den and a poor user[8] drops dead. Obviously, it serves no purpose, as the service is not part of the boot process anymore, so let's remove it for good! About the service, it may not be useful at boot, but it can be started to pick up changes in vconsole.conf and set the consoles accordingly. But wait, this doesn't work anymore: the service is never started at boot (remember f76d2aa6), so switch-to-configuration.pl will not restart it. Fortunately it can be repaired: here I install a new unit which does *nothing* on start, but restarts the real service when reloaded. This perfectly reproduces the original behavior, hopefully without the original bugs too. The End? [1]: cc54211069 [2]: f6ba8671d8 (diff-84849fddcef81458f69725dc18c6614aade5c4f41a032b6908ebcf1ee6740636) [3]: 8125e8d38e [4]: https://web.archive.org/web/20180603130107/https://github.com/NixOS/nixpkgs/issues/22470 [5]: https://github.com/NixOS/nixpkgs/issues/81138 [6]: https://web.archive.org/web/20180603130107/https://github.com/NixOS/nixpkgs/issues/22470#issuecomment-330930456 [7]: f76d2aa6e3 [8]: https://github.com/NixOS/nixpkgs/issues/107341		2021-02-21 10:27:34 +01:00
..
fonts	treewide: fix double quoted strings in meta.description	2021-01-24 19:56:59 +07:00
gtk	gtk-icon-cache: get native gtk3 for icon cache	2020-03-06 00:45:48 -05:00
krb5	nixos/krb5: add list to example configuration	2020-08-25 17:18:56 +02:00
xdg	nixos/xdg/portal: fix loading portals from systemd service	2021-01-11 19:22:22 -05:00
appstream.nix	nixos/modules: remove trailing whitespace	2020-08-07 14:45:39 +01:00
console.nix	nixos/console: fix console setting reloading	2021-02-21 10:27:34 +01:00
debug-info.nix
gnu.nix	nixos/modules: stdenv.lib -> lib	2021-01-17 21:40:51 +01:00
i18n.nix	treewide: fix double quoted strings in meta.description	2021-01-24 19:56:59 +07:00
iproute2.nix
ldap.nix	Merge pull request #98731 from mayflower/ldap-nss-optional	2020-12-12 10:53:39 +01:00
locale.nix
malloc.nix	nixos/malloc: fix Scudo	2020-11-17 09:11:31 -05:00
networking.nix	treewide: fix double quoted strings in meta.description	2021-01-24 19:56:59 +07:00
no-x-libs.nix	beam-packages: move wxSupport arg up to package set, add beam_nox	2021-01-24 21:04:52 +01:00
nsswitch.nix	nixos/nsswitch: improve error message	2020-05-11 16:14:51 +02:00
power-management.nix	nixos/power-management: always run systemctl of the currently running systemd	2020-05-21 10:28:29 +02:00
pulseaudio.nix	treewide: fix double quoted strings in meta.description	2021-01-24 19:56:59 +07:00
qt5.nix	nixos/qt5: support adwaita-dark theme	2020-04-05 08:38:08 +03:00
resolvconf.nix	nixos/resolvconf: always run systemctl of the currently running systemd	2020-05-21 10:29:22 +02:00
shells-environment.nix
swap.nix	utillinux: rename to util-linux	2020-11-24 12:42:06 -05:00
sysctl.nix
system-environment.nix
system-path.nix	nufraw: init at 0.43-3	2021-01-07 22:41:34 +01:00
terminfo.nix
unix-odbc-drivers.nix
update-users-groups.pl	Merge pull request #41966 from aneeshusa/allow-mutable-shells-for-declarative-users	2020-12-31 02:03:22 +01:00
users-groups.nix	Merge pull request #110627 from 4z3/use-real-user-name-for-per-user-packages	2021-02-15 12:45:24 +01:00
vte.nix	nixos: add freedesktop/gnome/myself maintainers	2020-04-01 20:53:09 -04:00
zram.nix	nixos/zram: add zramSwap.memoryMax option	2020-11-25 13:43:38 +00:00