Shell when included with `packagesFrom` stops building

[zmrocze]

Describe the bug

Given:

devshells.default.devshell = {
  name = "Haskell shell";
  packagesFrom = [ config.devShells.haskell ];
}

The default shell fails to build eventhough the original haskell shell builds. The default shell is empty otherwise and doesn't define any additional commands or dependencies.

Steps To Reproduce

Reproduction exists in the flake: https://github.com/zmrocze/reproduce-haskell.nix-template-shell-doesnt-build. Run:

nix develop github:zmrocze/reproduce-haskell.nix-template-shell-doesnt-build#default

and observe a failed build with:

error: collision between `/nix/store/xvfiswlgj9m2v5xhx1i09rsny9w6470n-vector-lib-vector-0.13.1.0/package.conf.d/package.cache' and `/nix/store/5mln06qzjihh3fp7na9ghz51rnni55gx-containers-lib-containers-0.6.5.1/package.conf.d/package.cache'

Then change default to haskell and observe a success, eventhough I expect shells to be the same.

Expected behavior

I expect the default shell to functionally the same as the haskell shell from which it originates. I wouldn't expect an error of this kind.