Hi, Continuing the struggle with the ghc and ruby build problems I stumbled into finding two kernel (signal) threads in addition to the main (user) thread. According to Neal on IRC there shouldn't be more than one kernel thread running. This could be due to some race condition (don't know yet where).
Anyway, adding a print statement at eglibc-2.11.2/mach/msgserver.c resolved the hang in the configuration of ghc6-6.10.1 +dfsg1/libraries/random :-) For more info see http://pastebin.com/RcJs0Nht Single stepping in msgserver.c also triggered the console printout: task 5040ee18 deallocating an invalid port 340/xxx, most probably a bug. I think we are on the track to find where the cause of the build problems are.