On NixOS every plugin PACKAGE op failed with "the plugin runner isn't
installed" on a box where the runner was installed, enabled and running.
`runner_command()` checked FHS locations exclusively — /usr/bin, the
/usr/lib + /usr/share pair behind it, and the ~/.local mirror the SteamOS
installer lays down. Nix ships punktfunk-scripting as a derivation of its
OWN, so its wrapper is neither beside the host binary nor anywhere under
/usr, and no rung could ever match. Service ops go through systemd and
were unaffected, which is what made it read as arbitrary: `plugins
status` said running/enabled while `plugins add` said not installed.
Resolution now matches punktfunk-encode-worker's: PUNKTFUNK_SCRIPTING ->
beside the host binary -> PATH -> /usr -> ~/.local. PATH is the rung Nix
lands on. The /usr rungs stay AFTER it rather than being dropped, because
a systemd unit's PATH need not include /usr/bin. As with the encode
worker the env override is deliberately not existence-checked — a named
path that is wrong should fail naming itself, not fall through to some
other runner. Lifted into a pure injected function so the whole table is
testable, which is also how the regression is pinned: removing the PATH
rung fails the NixOS row specifically.
Second half, and the reason the Rust change alone would not have fixed
the console: the NixOS module now puts the runner on the HOST UNIT's
`path`. The console installs plugins from inside the host service, whose
PATH is exactly that unit list — `environment.systemPackages` only ever
covered an operator's interactive shell. Without it the CLI would have
been fixed and the console would not. module-check.nix gains both the
positive and the negative assertion, so CI's `nix flake check --no-build`
holds the property.
The error text named only apt and SteamOS; it now names NixOS and the
override. The ~/.local/bin symlink workaround is no longer needed.
enricobuehler
4ebe7d1185