Panic: mkNoTick: Breakpoint loading modules with -O2 via API

[JeanPhilippeMoresmau]

I load a trivial module via the API. I get a panic: GHCBugs.exe: GHCBugs.exe: panic! (the 'impossible' happened)

(GHC version 7.4.1 for i386-unknown-mingw32):

mkNoTick: Breakpoint

If I pass -O2 in the options. Without -O2 the module loads.

I attach the source code using the API to the ticket. The module I try to load just says: module Main where

main::IO() main = print "Hello Fay"

[JeanPhilippeMoresmau]

Code using the API exhibting the issue

[simonmar]

GHCi normally runs with optimisation off, so it's not entirely surprising that using the interpreter with optimisation on exposes new bugs. We should look into it though.