Hello, I am trying to load a Haskell module in a C program as a dynamically-loaded plugin via FFI. I am able to compile and link successfully, but I find the following crash. #0 0x00007f16147da9e7 in ?? () from /usr/lib/ghc/libHSrts_debug-ghc7.4.1.so #1 0x00007f16147e0970 in hs_init_ghc () from /usr/lib/ghc/libHSrts_debug-ghc7.4.1.so #2 0x00007f16147e0795 in hs_init () from /usr/lib/ghc/libHSrts_debug-ghc7.4.1.so #3 0x00007f1614a44ece in plhaskell_plmain (fcinfo=<optimized out>) at plhaskellc.c:26 #4 0x0000000000565e1a in ExecMakeFunctionResult () #5 0x00000000005682f2 in ExecProject () #6 0x000000000057849a in ExecResult () #7 0x0000000000561648 in ExecProcNode () #8 0x000000000055ea5a in standard_ExecutorRun () #9 0x0000000000628577 in PortalRunSelect () #10 0x0000000000629900 in PortalRun () #11 0x0000000000625bec in PostgresMain () #12 0x00000000005eb429 in ServerLoop () #13 0x00000000005ebd3c in PostmasterMain () #14 0x0000000000453d20 in main () In the trace above, one can see that I am linking against the debugging Haskell runtime. hs_init_ghc is called with dual NULL arguments. Is that cause for concern? I noticed that RtsStartup.c does some questionable stuff in a module context right away, such as calling "setlocale". Are there other things I need to watch out for? Do I need to build ghc from source in order to debug this further? Any advice would be appreciated. This is on Ubuntu 12.04. Cheers, M