I succeeded to attach gdb to a regrtest slave process stuck in test_io... but somehow attaching the process into gdb unblocked the process... and the test completed.


Sadly, the first time that I attached the process, I forgot to allow a directory to load python-gdb.py. So I had to detach and attach again the process to get a working "py-bt" command. Maybe this action unblocked Python. It's hard to say.

(gdb) py-bt
Traceback (most recent call first):
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/_pyio.py", line 1126, in _flush_unlocked
    def _flush_unlocked(self):
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/_pyio.py", line 1104, in write
    self._flush_unlocked()
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/_pyio.py", line 1302, in write
    return BufferedWriter.write(self, b)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/test_io.py", line 1186, in check_writes
    self.assertEqual(bufio.write(contents[n:n+size]), size)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/test_io.py", line 1723, in test_writes_and_peek
    self.check_writes(_peek)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/unittest/case.py", line 329, in run
    testMethod()
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/unittest/case.py", line 393, in __call__
    return self.run(*args, **kwds)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/unittest/suite.py", line 108, in run
    test(result)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/unittest/suite.py", line 70, in __call__
    return self.run(*args, **kwds)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/unittest/suite.py", line 108, in run
    test(result)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/unittest/suite.py", line 70, in __call__
    return self.run(*args, **kwds)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/support/__init__.py", line 1461, in run
    test(result)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/support/__init__.py", line 1535, in _run_suite
    result = runner.run(suite)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/support/__init__.py", line 1626, in run_unittest
    _run_suite(suite)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/test_io.py", line 3367, in test_main
    support.run_unittest(*tests)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/regrtest.py", line 1361, in run_the_test
    indirect_test()
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/regrtest.py", line 1375, in dash_R
    run_the_test()
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/regrtest.py", line 1239, in runtest_inner
    huntrleaks)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/regrtest.py", line 1044, in runtest
    return runtest_inner(test, verbose, quiet, huntrleaks, pgo, testdir)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/regrtest.py", line 513, in main
    result = runtest(*args, **kwargs)
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/regrtest.py", line 2025, in main_in_temp_cwd
    main()
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/test/regrtest.py", line 2038, in <module>
    main_in_temp_cwd()
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/runpy.py", line 174, in _run_module_as_main
    "__main__", fname, loader, pkg_name)

(gdb) where
#0  0x0050b6fd in PyEval_EvalFrameEx (
    f=Frame 0xb6bd1634, for file /buildbot/buildarea/2.7.ware-gentoo-x86.refleak/build/Lib/_pyio.py, line 1126, in _flush_unlocked (self=<BufferedRandom(_raw=<PyMockRawIO(_write_stack=['\x00', '\x01', '\x02', '\x03', '\x04', '\x05', '\x06', '\x07', '\x08', '\t', '\n', '\x0b', '\x0c', '\r', '\x0e', '\x0f\x10', '\x11\x12', '\x13\x14', '\x15\x16', '\x17\x18', '\x19\x1a', '\x1b\x1c', '\x1d\x1e', '\x1f ', '!"', '#$', '%&', "'(", ')*', '+,', '-./', '012', '345', '678', '9:;', '<=>', '?@A', 'BCD', 'EFG', 'HIJ', 'KLM', 'NOP', 'QRS', 'TUV', 'WXY', 'Z[\\]', '^_`a', 'bcde', 'fghi', 'jklm', 'nopq', 'rstu', 'vwxy', 'z{|}', '~\x7f\x80\x81', '\x82\x83\x84\x85', '\x86\x87\x88\x89', '\x8a\x8b\x8c\x8d', '\x8e\x8f\x90\x91', '\x92\x93\x94\x95', '\x96\x97\x98\x99\x9a', '\x9b\x9c\x9d\x9e\x9f', '\xa0\xa1\xa2\xa3\xa4', '\xa5\xa6\xa7\xa8\xa9', '\xaa\xab\xac\xad\xae', '\xaf\xb0\xb1\xb2\xb3', '\xb4\xb5\xb6\xb7\xb8', '\xb9\xba\xbb\xbc\xbd', '\xbe\xbf\xc0\xc1\xc2', '\xc3\xc4\xc5\xc6\xc7', '\xc8\xc9\xca\xcb\xcc', '\xcd\xce\xcf\xd0\xd1', '\xd2\x...(truncated), 
    throwflag=0) at Python/ceval.c:1094
#1  0x0051a9e8 in PyEval_EvalCodeEx (co=0xb6ccdda8, 
    globals={'BufferedReader': <ABCMeta(_abc_cache=<WeakSet(data=set([<weakref at remote 0xb6c21434>, <weakref at remote 0xb6bcc8b4>]), _pending_removals=[], _remove=<function at remote 0xb6687c64>, _iterating=set([])) at remote 0xb668a4cc>, peek=<function at remote 0xb6687ad4>, _abc_negative_cache_version=26, tell=<function at remote 0xb6687bc4>, read=<function at remote 0xb6687a34>, __doc__=u'BufferedReader(raw[, buffer_size])\n\n    A buffer for a readable, sequential BaseRawIO object.\n\n    The constructor creates a BufferedReader for the given readable raw\n    stream and buffer_size. If buffer_size is omitted, DEFAULT_BUFFER_SIZE\n    is used.\n    ', __init__=<function at remote 0xb6687994>, _reset_read_buf=<function at remote 0xb66879e4>, _abc_negative_cache=<WeakSet(data=set([]), _pending_removals=[], _remove=<function at remote 0xb66b7da4>, _iterating=set([])) at remote 0xb668a0a4>, __module__='_pyio', __abstractmethods__=frozenset([]), _peek_unlocked=<function at remote 0xb6687b24>, _read_unlocked=<function a...(truncated), 
    locals=0x0, args=0xb6c1cb50, argcount=1, kws=0xb6c1cb54, kwcount=0, defs=0x0, defcount=0, closure=0x0) at Python/ceval.c:3604
#2  0x0051d618 in fast_function (func=<function at remote 0xb6687e94>, pp_stack=0xbfbcc660, n=1, na=1, nk=0) at Python/ceval.c:4467
#3  0x0051d283 in call_function (pp_stack=0xbfbcc660, oparg=0) at Python/ceval.c:4392
(...)