feat: replace everything with dream2nix

[yusdacra]

This PR removes support for all "build platforms" and only uses dream2nix, essentially meaning nix-cargo-integration won't have to deal with maintaining a common interface for builders.

• figure out how to let users switch between different builders / translators in dream2nix

Resolves #55
Resolves #49

[kkharji]

Interesting, I'm having some issues with trying to append to postInstall script using buildRustPackage. Tried crateOverrides but no luck. Let me switch here and test it out.

[kkharji]

I'm building a library and I got the following error:
trace: warning: couldn't find a package with a binary to use as mainPackage.

my flake.nix https://gist.github.com/tami5/8058546f8522466dfc97ab6ac72a40b5

also same issue with cargo command not found

@nix { "action": "setPhase", "phase": "buildPhase" }
building

running: cargo build --release
/nix/store/0qlq4s175mzlx9g0aqcdk95j92g1z7mf-stdenv-darwin/setup: line 1364: cargo: command not found

edit: oh it unpacking dummy-src not my src, maybe because of trace: warning: couldn't find a package with a binary to use as mainPackage. ?

edit: inspected dummy-src, has my cargo but empty files
edit: add library to nix metadata in cargo.tml; no effect

[yusdacra]

also same issue with cargo command not found

@nix { "action": "setPhase", "phase": "buildPhase" }
building

running: cargo build --release
/nix/store/0qlq4s175mzlx9g0aqcdk95j92g1z7mf-stdenv-darwin/setup: line 1364: cargo: command not found

Hmm, that's interesting. That should not happen, if you could give a minimal reproducible example it would be appreciated. The flake.nix looks fine though.

edit: oh it unpacking dummy-src not my src, maybe because of trace: warning: couldn't find a package with a binary to use as mainPackage. ?

edit: inspected dummy-src, has my cargo but empty files edit: add library to nix metadata in cargo.tml; no effect

That is crane's dependency only derivation, so that is expected. The warning is for when dream2nix can't find a binary package, it should probably be removed.

[kkharji]

Hmm, that's interesting. That should not happen, if you could give a minimal reproducible example it would be appreciated. The flake.nix looks fine though.

Sure here you go https://github.com/tami5/Yabai.spoon/pull/1, still the same issue.

That is crane's dependency only derivation, so that is expected. The warning is for when dream2nix can't find a binary package, it should probably be removed.

Interesting so it wasn't taken in consideration.

[yusdacra]

This is mostly ready now, the only things I want to do before merging are:

• allow users to change the builder, which has to be implemented in dream2nix first
• fix the dream2nix bug that causes an infinite recursion

[yusdacra]

Stuff left to fix:

• figure out why buildRustPackage is not using the correct toolchain
• figure out why crane cant build multiple-git and basic-git