"ghc: panic! (the 'impossible' happened)"

When running tasty-hunit tests through cabal repl, I get the following error:

ghc: panic! (the 'impossible' happened)
  (GHC version 7.8.3 for x86_64-apple-darwin):
	Loading temp shared object failed: dlopen(/var/folders/l6/v2vhn_3j6bb1yvp6k5sh2hv80000gp/T/ghc80357_0/ghc80357_61.dylib, 9): Symbol not found: __hpc_tickboxes_horsezmcontrolzm0zi1zi0zi0_HorseziCommands_hpc
  Referenced from: /var/folders/l6/v2vhn_3j6bb1yvp6k5sh2hv80000gp/T/ghc80357_0/ghc80357_61.dylib
  Expected in: flat namespace
 in /var/folders/l6/v2vhn_3j6bb1yvp6k5sh2hv80000gp/T/ghc80357_0/ghc80357_61.dylib

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

I have a hunch that it's because I enabled the following flags in my .cabal file, since I didn't get the exception before adding them:

Test-Suite test-horse
    ...
    GHC-Options:      -fhpc -hpcdir dist/hpc/horse-control-1.0

When I run the tests via cabal test, I don't get the exception.

I've created a branch that showcases the crash: https://github.com/bgwines/horse-control/tree/ghc-panic

Repro steps:

• clone repo
• cd to repo
• run cabal repl
• run :l Tests/test-horse.hs
• run main

Reproducability: 100%

Please feel free to contact me if there's information lacking, here! :)

Trac metadata

Trac field	Value
Version	7.10.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture