Message 307763 - Python tracker
For added fun: at least one part of the standard library doesn't expect None returns from read() in the buffering layer. >>> import os >>> r, w = os.pipe2(os.O_NONBLOCK) >>> f = os.fdopen(r, 'r') >>> f.read() Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/izbyshev/workspace/cpython/Lib/codecs.py", line 321, in decode data = self.buffer + input TypeError: can't concat NoneType to bytes Note that nonblock-none.patch doesn't seem to address that.