Open Source®™© feature of the day
The the people who, for lack of a better word, "develop" the Free Software Foundation's "configure" program, have decided that it's really important that configure check for the existance of a f77 compiler along with the approximately 65,000 other stupid things that configure checks for.
They can't look in /usr/local for anything, oh no, because that would be, um, THE TRADITIONAL PLACE TO PUT THIRD-PARTY SOFTWARE ON A UNIX BOX, but they can, along with the ongoing breakage of their "portability" support on Linux machines (if you're running on a Linux box that doesn't have the gnu bloatware de jour, it's a coinflip whether a particular "configure"d package will properly configure. And G-d help you if you take defaults on "configure"d prerequisites, because it will put them into /usr/local and then the next "configure"d package won't even find them. Yay Linux!) always check to see if you're running f77.
Sheesh.