The prototypes difference between platform is really annoying, since it's hard to always match the system on, and prevent warning on bad types. I try now to always use BRK emulation on all platform that do not match the prototype used in ACK. the PM script should be changed to set this correctly during setup.
Mac OS X seems to have some difficulties with brk/sbrk (maybe with the
4MB heap limit), and replace all the allocation logic will be prone to
errors, I'll add a new define and lib to emulate brk/sbrk using more
standard allocation methods. By default the heap is 64MB, it should be
enough.
