Thanks Henrik!!
I think I figured out why Cog some times terminates when downloading large files on OSX;
An oversleep which is interrupted can be returned as a t_time struct with tv_sec -1 and tv_nsec close to 999999999.
The while check is
nanosleep (&naptime, &naptime) == -1 && naptime.tv_sec > 0 1|| naptime.tv_nsec > MINSLEEPNS
or so, so when an interrupt is encountered which has tv_sec = -1, you will get the invalid argument error.
rewriting it to
naptime.tvsec > -1 && naptime.tv_nsec > MINSLEEPNS && nanosleep(&naptime, &naptime) == -1
I no longer had crashes in 99% of hte cases when evaluating the following test:
HTTPSocket httpGetDocument: 'http://www.squeaksource.com/Pharo/Morphic-stephane_ducasse.334.mcz'.
I've attached the sqUnixHeartbeat.c.
Cheers,
Henry