Remove nix support

[willeccles]

Nix is not supposed to be used on NixOS the way that cpm implements it,
and it's (to the best of my knowledge) not the best way on other
platforms as well. We also do not support non-platform-specific package
managers, so the precedent says we should remove this one.

[willeccles]

@6gk and @buffet, thoughts?

[willeccles]

Also, input from @mlvzk would be appreciated.

[eepykate]

not the best way on other platforms as well.

Hence why it's at the bottom.

I dunno, I like having it as a fallback, especially coupled with pm=nix cpm i nixpkgs.bad existing.

Admittedly I haven't touched nix in ages and my nix PM install is broke so take that with a grain of salt.

[foxsouns]

maybe as a middle ground we could have nix as an explicit only thing
like it only runs if pm=nix, and maybe have a message saying on firstrun "the nix implementation here is not to spec, and is not supported."

[willeccles]

maybe as a middle ground we could have nix as an explicit only thing like it only runs if pm=nix, and maybe have a message saying on firstrun "the nix implementation here is not to spec, and is not supported."

This would require adding logic that is not used for any other package manager, and it wouldn't make much sense to have a special case for this.

[foxsouns]

fair

[eepykate]

But yeah, as I said, I haven't used nix in like 5 months (last time was helping ladle with something iirc?) & I've never used it in cpm.

Sooo major grain of salt there lmao.

I don't have anything against removing it, of course, i just kinda like having it as a potential fallback.

[willeccles]

I think since @buffet approved it and is probably the most experienced with nix by a wide margin, I'll go ahead and merge.

[eepykate]

👍