Cannot install RMagick as there is an error about nob being able to find some shared libraries.
After reading the RMagick installation FAQ it seem there is a problem with the LD_LIBRARY_PATH that cannot find the needed libraries as they are installed in /usr/local/lib instead of /usr/lib.
Doing a quick search revealed that people suggest that the LD_LIBRARY_PATH shouldn’t be changed, for various reasons.
So, the quick solution is to create a couple of symbolic links for the libraries that cannot be found, ie:
sudo ln -s /usr/local/lib/libMagickWand.so.4 /usr/lib/libMagickWand.so.4
ln -s /usr/local/lib/libMagickCore.so.4 /usr/lib/libMagickCore.so.4