Fri Apr 28 11:50:49 EDT 2006 rsc
    This is not correct.  <unistd.h> is POSIX, so checking _POSIX_SOURCE is correct.
	Also, please run "mk all" in /sys/src/ape to check these changes before
	submitting them.  That should catch most problems with the build.
	
	Thanks.
	Russ