It looks like `gitCommitStamp` is the new "entrypoint" for setting this
information.
Fixes#9996.
Signed-off-by: Cole Helbling <cole.helbling@determinate.systems>
Another solution would be to copy the `.defaults` file alongside the
service file, and set the `EnvironmentFile` to point to that, but it
would still be hardcoded (as the `.defaults` file would be stored in the
Nix store), so I figured that this is a good solution until there is a
proper NixOS module.
Fixes#9995.
Signed-off-by: Cole Helbling <cole.helbling@determinate.systems>
Since the tailscale derivation already has a `pkgs` binding, we can
use `pkgs.lib`. Alternatively, we could have used `nixpkgs.lib`, as
`fileContents` doesn't need a system to use (anymore?).
Signed-off-by: Cole Helbling <cole.helbling@determinate.systems>