[Nix-dev] pkgs/development/libraries/haskell/cabal/cabal.nix generates dangling symlinks

[Marc Weber]

Hi Simon,

What is the background?

Dependency chain:

base -> regex -> other_lib

in order to use other_lib ghc must find regex and base.

Currently ghc is wrapped passing all paths found in $PATH to ghc and
ghc-pkg etc using -package-conf.
that's why ghc usually does find them on NixOS/nixpkgs.

That's why ghc-pkg does not show core packages - this should be fixed as
well (?)

So in order to use other_lib regex and base must be in PATH.

That's the reason why kind of propagated-user-env-packages should be
used.


In hack-nix I added to the cabal builder explicitly :
{
  propagatedBuildNativeInputs = deps;               
}

Probably that's because I never encountered this issue.

AFAIK Andres Loeh (kosmikus) is the maintainer of that code.

So without investigating any further this looks like a bug to me.

I'd wait 24h or so - maybe Andres Loeh replies.

Marc Weber