unable to use non-glibc nss modules when setting services.nscd.package = pkgs.unscd;

[flokli]

I tried to give unscd a go, and set services.nscd.package = pkgs.unscd;.

While unscd successfully starts up as nscd.service, it seems it's not able to discover the NSS modules we point it to via LD_LIBRARY_PATH.

Repro:

Configure your system like this:

{
  services.nscd.package = pkgs.unscd;
}

Try to run a query requiring a non-glibc NSS module:

$ systemd-run --pty --property=Type=oneshot --property=DynamicUser=yes --property=User=iamatest whoami
/run/current-system/sw/bin/whoami: cannot find name for user ID 63915

If I drop the services.nscd.package option, the call works:

$ systemd-run --pty --property=Type=oneshot --property=DynamicUser=yes --property=User=iamatest whoami
Running as unit: run-u882.service
Press ^] three times within 1s to disconnect TTY.
iamatest

cc @erikarvstedt @Ericson2314

[flokli]

6eed70c from #194916 provides a reproducer for this. I think it's a general unscd problem.

[flokli]

I'm tempted to say there's nothing to be done for nixpkgs here, so we should either see if upstream fixes this, or switch to an alternative.