# Pastebin HqlctmEg
In the following nix-expression:

```
{ pkgs ? import ./pkgs.nix { } }:

with pkgs.haskell.lib;

let
  hsPkgs = pkgs.haskellPackages;

  addTestDependencies = d: pkgs.haskell.lib.addBuildDepends d (with pkgs; [minio dynamodb-local]);
in

rec {
  jaws-local = doCoverage (doHaddock (addTestDependencies (hsPkgs.callCabal2nix "jaws-local" ./jaws-local {                          })));
  jaws       = doCoverage (doHaddock (addTestDependencies (hsPkgs.callCabal2nix "jaws"       ./jaws       { inherit jaws-local;      })));
  jaws-prime = doCoverage (doHaddock (addTestDependencies (hsPkgs.callCabal2nix "jaws"       ./jaws       { jaws-local = dontCoverage jaws-local; })));
}
```

`nix-build release.nix -A jaws-local` works.
`nix-build release.nix -A jaws` fails with:

```
hpc: can not find jaws-local-0.2.1.0-Gm8wwZY3p5EpJSsbIaNtS/Tiny.JawsLocal.Cont.Asynchronous.Process in ./.hpc, ./dist/hpc/vanilla/mix/j
aws-0.4.1.0, ./dist/hpc/vanilla/mix/integration-tests
CallStack (from HasCallStack):
  error, called at libraries/hpc/Trace/Hpc/Mix.hs:122:15 in hpc-0.6.0.3:Trace.Hpc.Mix
builder for '/nix/store/x0l5bqbrvk1p8mbypmayrlx5spllq3rz-jaws-0.4.1.0.drv' failed with exit code 1
error: build of '/nix/store/x0l5bqbrvk1p8mbypmayrlx5spllq3rz-jaws-0.4.1.0.drv' failed
```

`nix-build release.nix -A jaws-prime` works.

What is it about building a dependency with coverage that causes
building to fail?