Appion

The warning in the python docs only indicate that it will block if the child stdout or stderr are connected to PIPE, but in this case only the stdin is connected to a PIPE. The output is connected to an open file object (logf), so not sure how the warning applies in this case. I guess the doc is wrong because it obviously fixes it to use communicate.

Other cases where this could hit us again in appion:

Checking where we use proc.wait():

grep -r "proc.wait()" * |grep -v svn

returns 165 lines. Those are not necessarily all bad because many do not redirect stdout,stderr to pipes or files, they just let it out through the parent process stdout/err. Can also check how many Popen() were created with stdout/err/in redirection:

grep -r Popen * | grep -v svn | grep std

returns 63 lines

I will try to fix as many as possible, but I think we don't have to worry about getting them all since no other problems have been reported.