attribute 'targetPrefix' missing

[goertzenator]

I have a complex nix build involving haskell.nix. When haskell.nix and nixpkgs are at very recent versions I get the following error:

error: attribute 'targetPrefix' missing

       at /nix/store/szd5blrcjblqbxg4hq092zayjdlzsrrr-source/overlays/cabal-pkg-config.nix:86:21:

           85|     installPhase = attrs.installPhase + ''
           86|       mv $out/bin/${attrs.targetPrefix}${attrs.baseBinName} \
             |                     ^
           87|         $out/bin/${attrs.targetPrefix}${attrs.baseBinName}-wrapped
(use '--show-trace' to show detailed location information)

The error goes away I use an older nixpkgs. After a few days of bisecting 20,000 nixpkgs revs I arrived at the following commit:

NixOS/nixpkgs@adc8900

This one mentions targetPrefix so it seems like the likely source. The other bisect candidate was NixOS/nixpkgs@734d7df

I'll dig into this more tomorrow, but wanted to get these findings out in case somebody knows immediately what is going wrong.

[andreabedini]

Fixed in #1838 I belive.