import error

[Aspirinkb]

1. python 3.6
2. dlib 19.7
3. Mac OS

When import dlib:

import dlib
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/Applications/PyCharm CE.app/Contents/helpers/pydev/_pydev_bundle/pydev_import_hook.py", line 21, in do_import
    module = self._system_import(name, *args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/dlib-19.7.99-py3.6-macosx-10.6-intel.egg/dlib/__init__.py", line 1, in <module>
    from .dlib import *
  File "/Applications/PyCharm CE.app/Contents/helpers/pydev/_pydev_bundle/pydev_import_hook.py", line 21, in do_import
    module = self._system_import(name, *args, **kwargs)
ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/dlib-19.7.99-py3.6-macosx-10.6-intel.egg/dlib/dlib.so, 2): Symbol not found: _PyClass_Type
  Referenced from: /usr/local/opt/boost-python/lib/libboost_python-mt.dylib
  Expected in: flat namespace
 in /usr/local/opt/boost-python/lib/libboost_python-mt.dylib

Any help?

[davisking]

http://dlib.net/faq.html#WhywontthePythonbindingscompilework

[Aspirinkb]

Yes, I have more than one copy of Python installed on my Mac and they are

1. /Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6
2. /System/Library/Frameworks/Python.framework/Versions/2.6/bin/python2.6
3. /System/Library/Frameworks/Python.framework/Versions/2.7/bin/python2.7
4. /usr/bin/python
5. ~/anaconda/envs/py35/bin/python
6. ~/anaconda/envs/py27/bin/python

I pip3 install dlib for python3.6. So, how should I complie Boost and dlib against python 3.6?

[davisking]

Run dlib's setup.py script with the python you want to use. As for boost, I don't know. I would refer to the boost documentation for instructions in your case.

[Aspirinkb]

I brew install boost-python --with-python3 and run python3 setup.py install --yes USE_AVX_INSTRUCTIONS. But same error when import dlib. I think I should try some other way of installing boost-python.

[Aspirinkb]

stackoverflow solution to correct boost-python error.

[Aspirinkb]

1. uninstall boost-python for python2
   brew uninstall boost-python
2. install boost-python for python3
   brew install boost-python --with-python3
3. change name of libboost_python3 to libboost_python
cd /usr/local/opt/boost-python/lib/
ls, and got something like this:

libboost_python-mt.a            libboost_python3-mt.a
libboost_python-mt.dylib        libboost_python3-mt.dylib
libboost_python.a               libboost_python3.a
libboost_python.dylib           libboost_python3.dylib

backup boost-python for python2 and change boost-python for python3:

mv libboost_python-mt.a libboost_python2-mt.a && cp libboost_python3-mt.a libboost_python-mt.a
mv libboost_python-mt.dylib libboost_python2-mt.dylib && cp libboost_python3-mt.dylib libboost_python-mt.dylib
mv libboost_python.a libboost_python2.a && cp libboost_python3.a libboost_python.a
mv libboost_python.dylib libboost_python2.dylib && cp libboost_python3-mt.dylib libboost_python.dylib

4. clone dlib from github and cd dlib
   python3 setup.py install --yes USE_AVX_INSTRUCTIONS

Done!

[davisking]

Sweet, thanks for reporting how to fix it :)

[MaffooBristol]

Thank you for the instructions! Slight typo though (needs double ampersand not single, otherwise it gets confused and tries to create daemons!)

mv libboost_python-mt.a libboost_python2-mt.a && cp libboost_python3-mt.a libboost_python-mt.a
mv libboost_python-mt.dylib libboost_python2-mt.dylib && cp libboost_python3-mt.dylib libboost_python-mt.dylib
mv libboost_python.a libboost_python2.a && cp libboost_python3.a libboost_python.a
mv libboost_python.dylib libboost_python2.dylib && cp libboost_python3-mt.dylib libboost_python.dylib

[drhoffma]

I found that using an older version of boost on macOS fixed things for me:

brew install homebrew/versions/boost155

[lucasjinreal]

The @Aspirinkb 's solution are not work at all. Still same error after do this.