New submission from Samuel Bayer <s...@mitre.org>:
This bug is probably related to issue 24560. This: >>> import subprocess, fcntl, os >>>> p = subprocess.Popen(["python", "-c", 'import time; time.sleep(5)'], stdin >>>> = subprocess.PIPE, stdout = subprocess.PIPE, stderr = subprocess.PIPE, >>>> universal_newlines= True) >>> fcntl.fcntl(p.stderr.fileno(), fcntl.F_SETFL, os.O_NONBLOCK | >>> fcntl.fcntl(p.stderr.fileno(), fcntl.F_GETFL)) >>> p.stderr.read() causes this: Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/codecs.py", line 321, in decode data = self.buffer + input TypeError: can't concat NoneType to bytes I'm assuming the problem is that the underlying unbuffered stream returns None and the incremental byte decoder that's induced by universal_newlines = True isn't expecting it. ---------- components: IO messages: 333883 nosy: sambayer priority: normal severity: normal status: open title: subprocess.Popen with universal_newlines and nonblocking streams failes with "can't concat NoneType to bytes" type: crash versions: Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue35762> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com