[Python] Cython unable to find shared object file

I am trying to link to my own C library from Cython, following the directions I've found on the web, including this answer:

Using Cython To Link Python To A Shared Library

I am running IPython through Spyder.

My setup.py looks like this:

from distutils.core import setup
from distutils.extension import Extension
from Cython.Build import cythonize
import numpy as np

setup(
ext_modules = cythonize(
[Extension("*",["*.pyx"],
libraries =["MyLib"],
extra_compile_args = ["-fopenmp","-O3"],
extra_link_args=["-L/path/to/lib"])
]),
include_dirs = [np.get_include()],
)


The file libMyLib.so is in /path/to/lib and it compiles fine.

I have a Python script in my IPython profile startup folder that does this

try:
os.environ["LD_LIBRARY_PATH"] += ":/path/to/lib"
except KeyError:
os.environ["LD_LIBRARY_PATH"] = "/path/to/lib"


I can confirm that this is running, because if I type os.environ["LD_LIBRARY_PATH"] into the IPython interpreter, it returns /path/to/lib

But when I try to load the Cython module (i.e. import mycythonmodule) I get:

ImportError: libMyLib.so: cannot open shared object file: No such file or directory


I've also tried putting libMyLib.so in other places to see if cython would find it:

• In the directory where Python is running
• On the Python path
• In the same folder as the cython module

But it still doesn't find the shared library. The only way I can get it to find the library is by dropping it in /usr/lib, but I don't want it there, I want to be able to set the library path.

Am I missing something?

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