It was failing at link time, some problem with terminatePID.
Re-implemented that to not use a C wrapper function, which cleared up the
problem. Removed old EvilLinker hack with must have been related to the
same problem.
Note that I have not tested this with older ghc's. In
f11f7520b5 I mention having tried this
approach before, and getting segfaults.. So, who knows. It seems to work
fine with ghc 7.10 at least.