Configuring packages affects devShell.tools builds also

[bglgwyng]

I found that when I customized packages, it affects the builds of devShell.tools.
So I did the following workaround to prevent the behavior.

{
  packages = packagesToOverride;
  devShell = {
    tools = _: with config.haskellProjects.default.basePackages; {
        cabal-install = cabal-install;
        ghcid = ghcid;
        hlint = hlint;
        haskell-language-server = haskell-language-server;
      };
  };
}

I'm not saying it's a bug, but I think we can have a better solution.
One thing I can think of is adding devShell.packages options whose default is haskellProjects.*.packages.

[srid]

One thing I can think of is adding devShell.packages options whose default is haskellProjects.*.packages.

I think that's a good idea.

[srid]

I see that you opened the PR #513

But I just realized something: if the devShell doesn't contain local packages, wouldn't that break normal development flow with cabal?

[bglgwyng]

Sorry I didn't check Codex's output carefully enough. I fixed the commit. In dev shell, ghc is still ghcWithPackages haskellProjects.foo.packages and only tools are built with devShell.packages whose default is basePackages.

[bglgwyng]

@srid Could you review my change again? I think that I fixed what you pointed out.