py2app and macholib error

[drsmith48@…]

Py2app and macholib raise the error "ValueError: New Mach-O header is too large to relocate". The patches for configure.ldflags in portconfigure.tcl described here

​https://bitbucket.org/ronaldoussoren/py2app/issue/93/mach-o-header-may-be-too-large-to-relocate ​http://www.danplanet.com/blog/2009/02/15/using-py2app-with-gtk/ ​https://trac.macports.org/ticket/29838

do not fix the error. I suspect some ports override default configure.ldflags. Also, I think OpenCV triggers the same error:

​http://stackoverflow.com/questions/13131024/py2app-error-for-opencv-macports-app-how-to-compile-opencv-with-headerpad-max-i

Error stack:

WARNING: Mach-O header may be too large to relocate
WARNING: Mach-O header may be too large to relocate
Traceback (most recent call last):
  File "setup.py", line 26, in <module>
    setup_requires=['py2app'],
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/core.py", line 152, in setup
    dist.run_commands()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/py2app/build_app.py", line 553, in run
    self._run()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/py2app/build_app.py", line 741, in _run
    self.run_normal()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/py2app/build_app.py", line 831, in run_normal
    self.create_binaries(py_files, pkgdirs, extensions, loader_files)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/py2app/build_app.py", line 978, in create_binaries
    platfiles = mm.run()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/macholib/MachOStandalone.py", line 140, in run
    node.write(f)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/macholib/MachO.py", line 119, in write
    header.write(f)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/macholib/MachO.py", line 314, in write
    self.synchronize_size()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/macholib/MachO.py", line 304, in synchronize_size
    raise ValueError("New Mach-O header is too large to relocate")
ValueError: New Mach-O header is too large to relocate
drsmith$

py2app's full output is attached.

Env: python27, py27-py2app, py27-macholib on OSX 10.8.

Any guidance would be helpful. There seems to be lots of confusion about this in trac and stack overflow.

Thanks.

[drsmith48@…]

py2app output

[jmroot (Joshua Root)]

As explained in your links, there is nothing py2app can do about this. The relocated header cannot be larger than the original.

[drsmith48@…]

How about macholib? I'm not sure where the bug lies.

[jmroot (Joshua Root)]

AIUI it's more like a limitation of the Mach-O format, in that to increase the size of the header you effectively have to re-link the file. So it could be viewed as a deficiency of macholib that it doesn't do that, but it's not like it's a simple fix, which is why install_name_tool can't do it either.

[spam4scott@…]

For future reference. I had begun posting "Same problem as above. Earlier, editing portconfigure.tcl did the trick, but with the newer MacPorts I confirm that this does not fix it; i.e., error persists despite fresh clean/reinstall of MacPorts, rebuilding with -headerpad... in portconfigure.tcl "

...However, this is now...

RESOLVED: Posting solution for future users: The issue resulted from my default python installation somehow getting switched from the MacPorts version in /opt/local/bin to the Apple version in /usr/bin. (No idea how. Lion->Mountain Lion upgrade, perhaps?)

MacPorts now comes with the required -headerpad,etc. modifications, so if you are still encountering the error that started this thread, run "which python" and if you see "/usr/bin/python", then set your path so that it checks /opt/local/bin first.

With this change -- i.e., using the actual MacPorts python instead of the 'default' (duhhh) -- the build finishes successfully and the executable application runs without problem.