failed to get current user: user: unknown userid 62583

[raboof]

Running the trustix daemon from the nixos module, it is running as a DynamicUser systemd module:

https://github.com/tweag/trustix/blob/9bf6f32ab9b28c49fdc12c6e7a847a2b6dc1aa00/packages/trustix/nixos/default.nix#L240-L246

If I understand correctly from http://0pointer.net/blog/dynamic-users-with-systemd.html, systemd should an actual user for this dynamic user, not just a PID. However, I only see a pid:

62583 1341 0.0 0.0 1312748 16264 ? Ssl 14:46 0:00 /nix/store/k17mjpk7hfbmvx9r2abh11rw24x97dlz-trustix-dev/bin/trustix daemon --state . --config /nix/store/yqpsksmayry4qmp6sicimzz6ck0ivxa8-trustix-config.toml

Then, when I try to publish a build (say, nix-build '<nixpkgs>' -A hello --check), it fails on not being able to find the user:

post-build-hook: time="2021-06-21T15:11:59+02:00" level=debug msg="Submitting mapping" storePath=/nix/store/vf8fb2avrxnnhc6n70dkqdlk25f61rwm-hello-2.10
post-build-hook: time="2021-06-21T15:11:59+02:00" level=debug msg="Dialing remote" address="unix:///run/trustix-daemon.socket"
post-build-hook: time="2021-06-21T15:11:59+02:00" level=fatal msg="could not submit: rpc error: code = Unknown desc = failed to get current user: user: unknown userid 62583"

The root cause might be in systemd not creating the user, but perhaps other trustix users have run into the same problem? I'm on nixos-unstable at 33d42ad7cf2769ce6364ed4e52afa8e9d1439d58