Error importing python-igraph
Question: I'm trying to install python-igraph package. Installation works without any
warning nor error, but then, when I try to import the module, I get an error:

    
    
    In [1]: import igraph
    ---------------------------------------------------------------------------
    ImportError                               Traceback (most recent call last)
    <ipython-input-1-8e950eb5d8d8> in <module>()
    ----> 1 import igraph
    
    /usr/local/lib/python2.7/site-packages/igraph/__init__.py in <module>()
         32 # pylint: disable-msg=W0401
         33 # W0401: wildcard import
    ---> 34 from igraph._igraph import *
         35 from igraph._igraph import __version__, __build_date__
         36 from igraph.clustering import *
    
    ImportError: dlopen(/usr/local/lib/python2.7/site-packages/igraph/_igraph.so, 2): Library not loaded: /usr/local/opt/gmp/lib/libgmp.10.dylib
      Referenced from: /usr/local/opt/glpk/lib/libglpk.36.dylib
      Reason: Incompatible library version: libglpk.36.dylib requires version 14.0.0 or later, but libgmp.10.dylib provides version 13.0.0
    

I can't manage to solve this problem. I saw [this
post](http://stackoverflow.com/questions/30505490/error-importing-igraph) and
tried their solutions but it did not work (the problem there was that glpk was
not installed, whereas for me it is installed).

To install it I did the following:

    
    
    brew tap homebrew/science
    brew install igraph
    sudo pip install python-igraph
    

And I checked that gmp and glpk were installed with `brew install igraph`

Does anybody have an idea of how I could manage to install it?

I'm working on Mac os x el capitan, with python2.7

Thanks for your help

## Edit from Tamás answer:

I checked, and gmp and glpk do come from homebrew. In fact,
`/usr/local/opt/gmp` is a symlink to `<path_to_>Cellar/gmp/6.0.0a`and
`/usr/local/opt/glpk` to `<path_to_>Cellar/glpk/4.57`.

I tried anyway to uninstall igraph (`brew uninstall igraph`), move somewhere
else the files in `/usr/local/opt` for gmp and glpk, and reinstall igraph. But
I get exactely the same error while importing the python module...


Answer: It seems like GMP and GLPK are not coming from Homebrew and they are not
compatible with each other. You have to fix the installation of GMP and GLPK.
Alternatively, you can uninstall `igraph`, then temporarily move GMP's and
GLPK's directories from `/usr/local/opt` to somewhere else, then install
`igraph` again. `igraph` will then "think" that GLPK and GMP are not available
on your machine and compiles itself without GLPK and GMP support (and disable
some features that require GLPK and GMP).

