I am sending this here and not to the bugs list under the assumption that I am doing something wrong...

I am trying to use the BNF converter tool. When I try it on simple examples, the first step (generation of the .y and .x files) goes through. When I run happy on the generated .y file, I get the following error:

happy.bin: internal error: stg_ap_pp_ret Please report this as a bug to glasgow-haskell-bugs@haskell.org, or http://www.sourceforge.net/projects/ghc/

Any help/guidance would be very appreciated.

This should never happen. Details please: what version of GHC, did you compile Happy from source or download binaries, if source: which version, can you send us the complete .y input to Happy, and anything else that might be relevant. Basically anything we need to reproduce the bug here. Cheers, Simon