Abort build when compiling with library-profiling enabled

[eigengrau]

I’ve noticed that when installing with library profiling enabled (as it might be in one’s ~/.cabal/config), building llvm-general (llvm-3.9 branch, --allow-newer) will fail with a linker error:

ByteCodeLink.lookupCE
During interactive linking, GHCi couldn't find the following symbol:
  mtlzm2zi2zi1zm6qsR1PHUy5lL47Hpoa4jCM_ControlziMonadziStateziClass_zdfMonadStatesStateT0zuzdcget_closure
This may be due to you not asking GHCi to load extra object files,
archives or DLLs needed by your current session.  Restart GHCi, specifying
the missing library using the -L/path/to/object/dir and -lmissinglibname
flags, or simply by naming the relevant files on the GHCi command line.
Alternatively, this link failure might indicate a bug in GHCi.

I’m not entirely sure if this originates here or in mtl, though this problem never arose when building other libraries which depend upon mtl.

IIRC some Cabalized packages issue an instructive error message when they’re being compiled with library-profiling enabled and subsequently abort the build (though I think usually the reason was that those packages messed with ghc-internals, e.g. ghc-vis). Depending on what’s causing the linker error here, maybe one would like to do the same.