[Python-Dev] Hmmm... __PyObject_NextNotImplemented when tracing lines

[skip at pobox.com]

    Alexander> I cannot reproduce this on my Mac.  It looks like you may
    Alexander> have an out of date python.exe in your sandbox.  Please check
    Alexander> that

    Alexander> $ nm python.exe | grep PyObject_NextNotImplemented
    Alexander> 00052940 T __PyObject_NextNotImplemented

    Alexander> has a "T" in the second column.

    Alexander> Note that this symbol seem to have been added recently:
    ...

I see what the problem is now.  I configured with --enable-shared.  Even
though my sandbox was up-to-date, my python.exe was current and my
libpython2.7.dylib held the symbol in question the *installed* version of
libpython2.7.dylib didn't have the symbol:

    % nm python.exe | grep PyObject_NextNotImplemented
    % nm libpython2.7.dylib | egrep PyObject_NextNotImplemented
    00054200 T __PyObject_NextNotImplemented
    % nm /Users/skip/local/lib/libpython2.7.dylib  | egrep PyObject_NextNotImplemented
    %

I've been bitten by this before.  When building with --enable-shared the
executable appears to have the installed shared library location bound into
it:

    % otool -L python.exepython.exe:
            /Users/skip/local/lib/libpython2.7.dylib (compatibility version 2.7.0, current version 2.7.0)
            /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 111.1.3)

Is this something that we can fix/work around?  It seems to me like a wart,
probably platform-dependent.

    Alexander> I am puzzled, however, that you don't see problems in a
    Alexander> non-coverage run.

Yeah, that mystifies me as well, especially given the above output from nm
and otool.

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