QGIS fails to load

Got the same problem on Linux Mint and finally fixed it.

The problem is that you've installed a few python libraries and one of them is a dependency of QGIS.

QGIS ~2.18 works fine with Scipy 0.17, and after upgrade this library to the newest version you have 0.19.

QGIS won't load with 0.19 because libqhull error.

All you need to do is downgrade, simply:

pip install scipy==0.17

And everything should be ok. You can also try with newer version but I'm not sure which one is good. I downgraded to 0.11 and it works form me again.

The same problem was pestering my QGIS on Fedora 27 for some time. QGIS was working fine, but if I wanted to install qgis-python, the libqhull error has prevented QGIS to start.

I did an ugly trick with compiling libqhull from the source and just overwrote the /usr/lib64/libqhull.so.7.2.0 with the manually compiled version and the problem was gone. The whole procedure was like:

1. Install qgis-devel

   dnf install qgis-devel
   

   (so the QGIS is broken and can not start)

2. Download qhull source, compile and overwrite the libqhull library

   cd /usr/local/src
   wget http://www.qhull.org/download/qhull-2015-src-7.2.0.tgz
   tar xzvf qhull-2015-src-7.2.0.tgz
   cd qhull-2015.2
   make
   cp -p lib/libqhull_r.so.7.2.0 /usr/lib64/libqhull.so.7.2.0
   

3. The QGIS should now run with Python Console enabled