closure-size: nix-serve: include bzip2 on PATH

[ttuegel]

This fixes nix-serve on the closure-size branch.

/cc @vcunat

[mention-bot]

By analyzing the blame information on this pull request, we identified @edolstra and @wkennington to be potential reviewers

[dezgeg]

Actually bzip2 should be coming from here: https://github.com/NixOS/nixpkgs/blob/closure-size/nixos/modules/services/networking/nix-serve.nix#L53. Which means we should do the output selection thing in systemd.services.<foo>.path as well.

[ttuegel]

@dezgeg Thanks! We'll do that in another PR. Closing this one.

[edolstra]

Well, arguably it's cleaner to fix it in the wrapper script than in the systemd service, since the latter makes it work for all users.

[ttuegel]

@edolstra Well, the wrapper script was missing bzip2, so if you weren't using the systemd service, it was already broken. But @dezgeg pointed out (rightly) that all systemd services are having their PATH set improperly; we should be doing map (pkg: pkg.bin or pkg) pkgs for the packages listed there.

[edolstra]

That seems hacky. Why pkg.bin or pkg? Why not pkg.bin or pkg.bin or ... or pkg? Rather, it should use whatever outputs would be installed into a user environment by default.

[ttuegel]

Rather, it should use whatever outputs would be installed into a user environment by default.

Yes, absolutely. That's what I meant. I may not have quoted the expression correctly. 😃

[dezgeg]

And for clarification: this is what the closure-size branch currently uses for choosing what to install in the user environment: pkg.bin or pkg.out or pkg.
#12653 for the discussion on that.

[ttuegel]

And for clarification: this is what the closure-size branch currently uses for choosing what to install in the user environment: pkg.bin or pkg.out or pkg.

No, because that PR was never merged.