Pierre Kisters
3acacc6388
nix-installer uninstall failed at `systemctl stop nix.mount` ("Job
failed") while programs started from the Nix store still ran: a terminal
session's tools, or apps that mapped Home Manager's mime.cache.
- Before nix-installer runs, after Home Manager is gone, uninstall scans
/proc for the user's processes whose exe, cwd, root, an fd or a mapped
file is in /nix, and lists them by name and PID (the shells it was
started from included; itself, its subshells and its curl | bash
pipeline skipped). Close them and press Enter to re-check, or abort;
with --yes or without a terminal it stops: "close these or reboot, then
run uninstall again". Nothing is killed (replaces the old kill prompt).
- nix-installer runs from a copy outside /nix.
- cleanup check H: a fake /proc (STEAM_FRAME_NIX_PROC) with programs from
the store stops before Nix; without them Nix is removed.
4.6 KiB
Cleanup and installer
How steam-frame-nix-cleanup and install.sh work. What steam-frame-nix
writes outside the Nix store, how to remove it, rollback and uninstall:
README, Changes outside Nix,
Rollback, Uninstall.
Cleanup
steam-frame-nix-cleanup (steamFrame.cleanup.package, module cleanup,
imported by every module) is install.sh cleanup, so the same code runs
with Nix (on every switch: cleanup --orphans --keep <what the configuration still uses>) and without it, from the script (bash, coreutils, findutils,
grep, sed, awk, jq, all in SteamOS' /usr/bin). Home Manager's
uninstall = true; runs cleanup --all from the activation. --quiet
prints only actions, deferrals and warnings.
It removes an artifact only when it is proven to be its own; anything else is reported as "left alone" and never touched:
| Artifact | Proof / rule |
|---|---|
debugger: VRWebHelper.DebuggerEnabled in steamvr.vrsettings |
~/.local/state/steam-frame-nix/steamvr-debugger.armed holds the value before (older versions: the empty marker steamvr-debugger, value before = absent). Restored once SteamVR is stopped; while it runs the runtime drop-in restores it when SteamVR stops. Also the runtime drop-in and restore script themselves. |
icons: hicolor/scalable/apps/<name>.svg |
links to Breeze in the store, listed in ~/.local/state/steam-frame-nix/icon-fallbacks (the icon-fallbacks script of 2026-09) |
firefox: user.js in Firefox profiles |
links to /app/etc/firefox/steam-frame-nix-desktop-user.js (left alone while the profile is in use), older links to *-firefox-*user.js and copies starting with the steam-frame-nix marker comment, and the values they left in prefs.js (only with Firefox closed) |
jellyfin |
the hwdec shim entries in the Jellyfin Flatpak's user override ~/.local/share/flatpak/overrides/org.jellyfin.JellyfinDesktop (nix-flatpak), an empty override file, and the shim copy of earlier versions in ~/.var/app/org.jellyfin.JellyfinDesktop (marker ~/.local/state/steam-frame-nix/jellyfin-hwdec-shim) |
ui-state: ~/.local/state/steam-frame-nix/ui-patches/<name>.json |
the dashboard patches' saved choices; --all only, never --orphans; stray *.json.tmp files |
launchers: /run/user/1000/steam-frame-nix/applications |
the entries of launchers (tmpfs); --all only (switches remove those of removed launchers themselves) |
screenshots: /run/user/1000/steam-frame-nix/screenshots |
a link to */userdata/*/760/remote/250820/screenshots (SteamVR screenshots); kept by --orphans --keep screenshots (while steamUserId is unset) |
pet: /run/user/1000/steam-frame-nix/vr-pet |
icon.png, a link to *-vr-pet-icons/*.png in the store (VR pet), its empty .lock and stray .icon.tmp.* links, then the directory if empty; kept by --orphans --keep pet (while pet.enable) |
dirs |
~/.local/state/steam-frame-nix and /run/user/1000/steam-frame-nix when empty |
Left by older versions
Of the rows above, only older versions wrote: the icon fallback links and
their list, the debugger marker steamvr-debugger, Firefox user.js copies
and links and their prefs.js values, the Jellyfin hwdec override entries
(and an empty override file) and the old shim copy.
Installer
What install.sh install sets up is listed in the README under
Set up by install.sh. The installer runs
systemctl --user against the outer session's user manager (the nested
desktop can't reach it with its own environment) and uses the installed
home-manager if there is one, else Home Manager's master.
uninstall removes Nix with nix-installer, which fails when it can't
unmount /nix (systemctl stop nix.mount). Before that it scans /proc
for processes using /nix: their exe, cwd, root or an fd links into
/nix, or maps names a file there (e.g. an app started before the
uninstall that mapped Home Manager's mime.cache). Only the user's own
processes are readable; the Nix daemon is nix-installer's to stop. Skipped:
the script itself, its subshells (descendants) and its process group (the
curl | bash pipeline). Its ancestors are listed with a hint to run
uninstall from another terminal. Nothing is killed: it asks to close them
and re-checks on Enter, or (--yes, no terminal) stops before Nix. A bash
from the Nix store re-executes the script with /usr/bin/bash first, and
nix-installer runs from a copy outside /nix. The check uses
STEAM_FRAME_NIX_PROC as a fake /proc (section H of
modules/cleanup/check.nix).