Specifying which compiler to use
When I run the catkin installation it appears that cmake is using the PGI compiler available on the system I am using. I did not explicitly tell it to use that, so I assume that it just decided that was the best one to use. However, while building the rospack package I get an error saying that it does not recognize the -Wall switch. I would like to force the build process to use the GNU compilers instead of the PGI one. Where can I change this?