The non-zstd (default) artifacts mode is causing deps rebuild

[dpc]

I was trying #322 and noticed that in my build, at the end of buildWorkspaceDepsOnly step, nix is doing bunch of shrinking ... and afterwards the buildWorkspace is rebuilding all the dependencies from scratch.

Edit: Just checked and it seems that v0.12.1 behaves correctly. It also does the shrinking but when buildWorkspace starts it only builds local crates as expected.

BTW. It still seems to me that nix should not mess with these files under ./target... seems sus, and takes extra time.

> cargo --version
cargo 1.67.0 (8ecd4f20a 2023-01-10)
> rustc --version
rustc 1.67.0 (fc594f156 2023-01-24)

[ipetkov]

Edit: Just checked and it seems that v0.12.1 behaves correctly. It also does the shrinking but when buildWorkspace starts it only builds local crates as expected.

@dpc just to be clear, are you only seeing this behavior on #322 but not in v0.12.1? If so we can move the convo there, otherwise we can investigate this further

[dpc]

I see it everywhere when I don't use zstd, and given that everything is fine with v0.12.1, it might not be actually any problem. (Though it looks weird and seems to waste time).

[ipetkov]

That might be from mkDerivation's various post-installation hooks (which seek to strip out debug info and compress files, etc.) which might be crawling all the symlinked cargo artifacts. You could try disabling those and see if that helps!

[dpc]

I'm unable to reproduce. No idea what did I do wrong/different.