unit testing - Pythons 3.8.2 subprocess.poll( ) hangs after being called 40 or 50 times

Question

I just upgraded to MacOS 11.2 which now uses Python 3.8.2. My test suite guarantees that printed output prints as the output is sent to the console by using the code snippet below. As verified by the print xxx or print yyy statements the code hangs after roughly 50 Unit Tests. This code has been working for roughly 4 years and of course was working just prior to the 11.2 system upgrade. Any ideas for work arounds would be appreciated.

print( '
running: ' + curFilePath.split('/')[-1] + ': ' + str(curVer))
p = subprocess.Popen(fullCMD, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

while True:     # Print output as it sent to console
    print( 'xxx' )
    nextline = p.stdout.readline().decode()
    if nextline == '' and p.poll() is not None:
        print( 'yyy' )
        break
    sys.stdout.write(nextline)
    sys.stdout.flush()

print( 'completed: ' + curFilePath.split('/')[-1] )

question from:https://stackoverflow.com/questions/66052620/pythons-3-8-2-subprocess-poll-hangs-after-being-called-40-or-50-times

Answer 1

Waitting for answers