After building the py3k branch (r72674) with GCC 4.4 on OS X 10.5.7/x86
using:

CC=gcc-mp-4.4 ./configure --with-pydebug && make

test_poplib.py is crashing with a Bus error:

Macintosh-4:py3k dickinsm$ ./python.exe Lib/test/test_poplib.py
test_dele (main.TestPOP3Class) ... ok
test_exceptions (main.TestPOP3Class) ... ok
test_getwelcome (main.TestPOP3Class) ... ok
test_list (main.TestPOP3Class) ... ok
test_noop (main.TestPOP3Class) ... ok
test_pass_ (main.TestPOP3Class) ... ok
test_retr (main.TestPOP3Class) ... ok
test_rpop (main.TestPOP3Class) ... ok
test_stat (main.TestPOP3Class) ... ok
test_top (main.TestPOP3Class) ... ok
test_uidl (main.TestPOP3Class) ... ok
test_user (main.TestPOP3Class) ... ok
testTimeoutDefault (main.TestTimeouts) ... ok
testTimeoutNone (main.TestTimeouts) ... ok
testTimeoutValue (main.TestTimeouts) ... ok
test__all__ (main.TestPOP3_SSLClass) ... Bus error (core dumped)

gdb backtrace attached.

Setting priority to release blocker until we figure out that this isn't
Python's fault.

More information: gcc-mp-4.4 is GCC 4.4 from macports. For
some reason the macports version of gcc is having problems, but
not the regular Apple version.

When I compile with gcc-4.2 from Apple, test_poplib.py passes.
When I compile with gcc-4.2 from macports, test_poplib.py fails as above.

Here's a small script, cut down from test_poplib.py, that generates the
Bus error. I'm still trying to work out whether the bug is in gcc,
Python, or libssl.

import socket, ssl
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
ssl_sock = ssl.wrap_socket(s)
ssl_sock.connect(('www.verisign.com', 443))
file = ssl_sock.makefile('rb')
file.close()
ssl_sock.close()

Even stranger is that the crash happens in debug mode, i.e. without
optimizations.

I'm still trying to work out whether the bug is in gcc,
Python, or libssl.

It was, of course, none of the above. It was a PEBCAK error.
I had two versions of openssl: one from macports and one from
OS X, and I was using the include files from one version and
linking against the other.

Sorry for the noise.