pyenv and installing certain Python packages

Question

I'm trying to install an older version of Python on my Mac. I'm currently running 2.7.9, but our production environment is running 2.7.6. (There is a compatibility issue with gevent and 2.7.9.)

I found pyenv which allows me to install various versions. I've installed pyenv with brew and installed 2.7.6. I then created a virtualenv with 2.7.6 with the following command:

mkvirtualenv my_env --python=/Users/dustin/.pyenv/versions/2.7.6/bin/python

It seems to work fine and I'm running Python 2.7.6. The problem I am running into is that I can't install certain packages with pip such as Cython or M2crypto. I get C compile errors.

clang: error: linker command failed with exit code 1 (use -v to see invocation)

error: command 'clang' failed with exit status 1

If I create a virtualenv without specifying the Python version, these packages install fine. How do I fix this?

Answer 1

It could be due to trying to run an older version of Python 2.7.x (like 2.7.6) on newer releases of OS X. If you are on OS X 10.10, that's very likely the problem. See http://bugs.python.org/issue21811 . You may need to add at least the patch for _osx_support.py . If not, try running pip with -v and update your question with the results.

Update: With the additional information you supplied, it is clear that you are running into the OS X 10.10 support issues that were fixed in the changes for Issue21811 released in 2.7.8. In particular, the configure changes are needed to correctly parse the two-digit minor version number ( 10 ); otherwise, the code in configure mistakenly thinks you are are running on a very old version of OS X and generates obsolete link directives. You should backport https://hg.python.org/cpython/rev/2672e30d9095 and https://hg.python.org/cpython/rev/a7ab09e00dbc .