I could only find 3 independent instances in the Mercurial tree.
Aliasing FC to $F77
configure.ac:707:FC=$F77
configure.ac:708:AC_SUBST(FC)
Adding the alias into the Makefiles
build-aux/common.mk:94:FC = @FC@
build-aux/common.mk:557: -e "s|%OCTAVE_CONF_FC%|\"${FC}\"|" \
In README.MacOS
etc/README.MacOS:157: export FC="/usr/bin/gfortran"
etc/README.MacOS:178: export FC="/usr/bin/gfortran"
etc/README.MacOS:394: export FC=/opt/local/bin/gfortran-mp-4.4
My test of commenting out the configure.ac would have taken care of the
first two.