Message 326206 - Python tracker

As in pty.spawn, once started, the parent process will be hanged, even if the child process is already dead (or a zombie), and must wait for a KeyboardInterrupt or else to terminate the whole process.

Thus, I propose to revise `_copy` function, where the parent process hung, to check if the child process is dead periodically and if so, terminate the whole process then return as shown in the patch file.