fails:Process.wait returns its childs pid
fails:Process.wait sets $? to a Process::Status
fails:Process.wait waits for any child process if no pid is given
fails:Process.wait waits for a specific child if a pid is given
fails:Process.wait waits for a child whose process group ID is that of the calling process
fails:Process.wait doesn't block if no child is available when WNOHANG is used
fails:Process.wait always accepts flags=0
fails:Process.wait coerces the pid to an Integer
windows:Process.wait raises an Errno::ECHILD if there are no child processes
