I just grabbed 5.03 from cvs and built it. Everything worked fine, except when I go to compile using ghc-inplace, it tells me:

invalid argument Action: hPutBuf Handle: {closed} Reason: illegal buffer size 0

It appears able to generate the .hi file, but not the .o. I ran with -v and attached the transcript.

I see you're using 5.02.1 to build with - could you perhaps upgrade to 5.02.3 and try again? Cheers, Simon