It seems that you are hitting a bug with version 3.80 of GNU make (I have just reproduced the problem myself)
You can either
1) upgrade GNU make to 3.81
or
2) delete (or comment out) the lines from $NWCHEM_TOP/src/config/makefile.h that are causing this problem to surface.
The lines from $NWCHEM_TOP/src/config/makefile.h that you want to delete or comment out are lines
1747 to 1752