WIP: Errno::ECHILD thrown from Process.waitpid
Let's untag one of specs and see what happens!
Errno::* are subclasses of SystemCallError
Add an Errno generator, move some code out of try
Merge remote-tracking branch 'origin/master' into errno-echild
Process#{wait,wait2,waitall}
Merge error_for_oserror and errno_for_oserror
Minimise the try block in error_for_oserror
Merge pull request #732 from jstepien/errno-echild

Errno::ECHILD thrown from Process.waitpid, some Process methods