> 1. it's a shame the tests are skipped for windows or macintosh, but it
> was just the same in the original version

Yeah... I'm probably not the best person for talking about this low
level stuff but since sockets seem to be the most portable thing
accepted by select.select, maybe a listening socket could be used
instead of a process pipe.

> 2. I don't think sys.platform[:3] can be equal to 'riscos'

You're right. The original version was that way and I didn't notice it
was wrong since I've put hands on unittest stuff only.
I think this could be fine:

- if sys.platform[:3] in ('win', 'mac', 'os2', 'riscos'):
+ if sys.platform in ('win16', 'win32', 'win64', 'mac', 'os2', 'riscos'):