Ctrl+C of parallel fabricate script does not exit correctly.

[Google Code Exporter]

What steps will reproduce the problem?
1. Start a parallel fabricate script (build.py) that creates multiple processes
2. Try to interrupt the script with Ctrl+C
3. Script fails to exit, and hangs.

What is the expected output? What do you see instead?
The script should exit. Possibly writing the dependency information for 
completed work.

Script prints errors for each running process, but fails to exit. Subsequent 
Ctrl+C operations cause the script to print further errors for each process, 
but the script still does not exit. Only workaround is Ctrl+Z to suspend and 
kill the precesses with 'killall build.py'.

Original issue reported on code.google.com by [e-mail] on 13 Sep 2013 at 12:33