nix: `shell flakeRef#` invokes ~/.nix-defexpr

[lylythechosenone]

Current Behavior

No response

Expected Behavior

No response

Steps To Reproduce

No response

Version

1.4.1

OS

• Darwin
• Linux
• Termux
• Windows

Shell

• Bash
• Elvish
• Fish
• Nushell
• Oil
• Powershell
• Xonsh
• Zsh

Anything else?

Same as #2817, but with nix shell instead of nix eval.

[lylythechosenone]

Actually, this seems to be an issue with ActionInstallables. It doesn't handle installables correctly in general. An installable (according to nix docs) can be:

• a flake ref (flake#package)
• a store path (/nix/store/foo)

ActionInstallables checks for flake values if the flake is ., but otherwise just checks for a package using the flake as a channel, which breaks quite quickly.

ActionFlakeRefs is also not correct here, because it does not complete store paths. Really, everything that uses ActionFlakeRefs right now should be using ActionInstallables, it's just broken.

[lylythechosenone]

@rsteube I'm fine with fixing this myself, unless you want to do it in that PR.

[rsteube]

yes, have a go

[lylythechosenone]

Actually, I may not be able to do this. I don't think I know the codebase well enough.

[lylythechosenone]

Basically, it needs to allow any of multiple situations:

1. a flake (from the system registry or from a url, like github:author/repo/commit; it would be nice to suggest branches for that one)
2. a flake with #package
3. a store path (any path starting with /nix/store; better yet, handle non-standard nix store locations)

I'm not sure how to express this "any of." If you could tell me that, I think I could do the rest.

@rsteube

[koffydrop]

I could have a go at fixing this if it's welcome? I already use a patch that handles my specific use cases, though some would suffer from long processing times.

[rsteube]

sure