[cbcoutinho]

I'm running OpenSUSE 42.1 Leap, and am trying to install various versions of OpenFOAM (2.4.x - 4.x) onto my system. I first installed 2.4.x without any issue, but then tried to run an example parallel case using the the scotch decomposition method - that ended up failing because OF24x wasn't installed using scotch. I checked that I had scotch installed on my system, as well as the development headers - that wasn't the problem.

I cleaned by build directory and tried reinstalling OF24x again and noticed I was getting errors because OF couldn't find the scotch headers (scotch.h and ptscotch.h) I've tried editing the etc/config/scotch.sh file (similar to how the instructions on the wiki say for CGAL), but that didn't work and the build failed making a number of libraries.

In the end I found out that OpenFOAM looks for scotch in the ThirdParty directory by default instead of the system, and since current ThirdParty 2.4.x git repo doesn't contain it, I had to copy it over from the ThirdParty 2.4.0 tgz folder. This means that for every OpenFOAM install, I need to have a copy of the scotch source in each respective ThirdParty directory, which doesn't seem ideal.

Questions:

1. Why is the scotch source directory not included in the ThirdParty 2.4.x repo?
2. How do you allow OpenFOAM to access your system's version of scotch?