Symptom of not finding CFITSIO in configure test:

checking for ffopen in -lcfitsio... no configure: error: CFITSIO library not found. Obtain it at ​http://heasarc.gsfc.nasa.gov/docs/software/fitsio or use --with-cfitsio to specify location. problem building psLib : failure in psconfigure

Solution from Paul Price and Gautham Narayan:

Add -L/path/to/lib to LDFLAGS in environment variables.

Theoretically this should also work in if instead added in 'psconfig.csh' (or 'psconfig.sh' if appropriate).