What I was trying to accomplish ------------------------------- I tried to upgrade numpy # pip install --upgrade numpy.../chaouche/build/numpy/numpy/numarray/_capi.c:198:undefined reference to `log10' collect2: ld returned 1 exit status error: Command "gcc -pthread -shared -Wl,--as-needed -Wl,--no-undefined -Wl,-z,relro -Wl,-O1 -Wl,--build-id -Wl,--enable-new-dtags build/temp.linux-i686-2.7/numpy/numarray/_capi.o -L/usr/lib -Lbuild/temp.linux-i686-2.7 -lpython2.7 -o build/lib.linux-i686-2.7/numpy/numarray/_capi.so" failed with exit status 1 ---------------------------------------- Rolling back uninstall of numpy Replacing /usr/lib/python2.7/site-packages/numpy-1.6.1-py2.7.egg-info Command /usr/bin/python -c "import setuptools;__file__='/home/chaouche/build/numpy/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --single-version-externally-managed --record /tmp/pip-lppaDW-record/install-record.txt failed with error code 1 Exception information: Traceback (most recent call last): ... InstallationError: Command /usr/bin/python -c "import setuptools;__file__='/home/chaouche/build/numpy/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --single-version-externally-managed --record /tmp/pip-lppaDW-record/install-record.txt failed with error code 1 What the problem was -------------------- I eventually figured out that they didn't link to the math library where all those symbols where defined (log10, sqrt, sincos etc.). I found that out by manually trying the gcc command with the -lm flag and it compiled fine. My question ------------ What files do I need to edit in order to add this -lm flag and install numpy correctly ?