Comment 1 for bug 1079184

I believe HAS_FOO are defined at preprocessor level, not at cmake level. DOLFIN_ENABLE_FOO should be set if you compile as "make demo_plot-qt" in the tree, but perhaps not if you compile stand-alone? Is that the issue?

It is possible to use FOO_FOUND instead, but that will fail if the libraries are installed, but disabled in the DOLFIN build. I guess that could be resolved by suitable #ifdefs.