podman: make work on darwin

[eraserhd]

• podman: Use path to find gvproxy on Darwin
• Revert "podman: remove darwin wrapper"

Motivation for this change

Make podman work on Mac.

This is a temporary solution to #141041, with notes on how to work with upstream's change once 4.0.0 is released.

This restores the wrapper for darwin. @zowoq mentions that this wrapper somehow wrote to the store, but I don't
see how that could be unless there is a problem with one of packages passed to lib.makeBinPath (in which case
removing the wrapper isn't the right fix).

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.05 Release Notes (or backporting 21.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

@marsam @zowoq

[zowoq]

This doesn't fix the problem I mentioned in #141041 (comment).

this wrapper somehow wrote to the store, but I don't see how that could be unless there is a problem

What I said was:

store paths get written to the vm config

See: #141041 (comment)

[zowoq]

Also the podman maintainers have previously discussed this sort of patching and we really don't want to carry what will basically be a permanent patch.

It may not seem like much to add a patch but needing to keep the podman, etc ecosystem in sync and up to date makes permanent patching problematic.

podman used find gvproxy from $PATH until upstream changed it to what was basically the worst possible option for us, it would really be for the best that it get resolved upstream. Disregard, got mixed up between gvproxy and qemu.

[eraserhd]

Hold up. I'm very confused.

So the package is broken and doesn't work on darwin, so we are removing the wrapper -- which AFAICT is unrelated to the breakage, but breaks it further. But we neither mark the package as broken nor remove darwin from its supported platforms?

And this solution contains a patch literally labelled "temporary", with a reference to the already-merged upstream fix, and instructions for when the already-merged upstream fix is released, but you are closing it because we won't carry permanent patches?

I can understand many reasons for not wanting to merge this, but your stated reasons don't make sense. Did you read the code?

[zowoq]

Sorry, seems like I managed to drop a comment from a review.

By permanent patching I was referring to patching to fix the qemu paths we could re-add the wrapper.

[zowoq]

I don't want to add this patch with 4.0.0 being released soon as it will complicate the update, we can deal with darwin after we've completed the upgrade.

[zowoq]

But we neither mark the package as broken nor remove darwin from its supported platforms?

podman can still be used as a remote, it's only podman machine (which by having the wrapper implies that we support it) that is broken.

[eraserhd]

Aha, I get it. Sorry for the grumpy.

[zowoq]

4.0 update is merged, PR to wrap gvproxy: #161130