bug#9795: Disabling fortran (what's it for?)

[Ryan Schmidt]

Hello, I'm writing on behalf of the MacPorts project. In MacPorts, many users 
(some of the tickets are listed below) have experienced a problem building 
libtool, where the shared library libltdl.dylib doesn't get built. It took 
awhile to identify that this was the problem, because the failure was silent; 
the libtool port seemed to install successfully, but did not contain 
libltdl.dylib, which caused various problems for other software down the road. 
Once we added a check to the libtool port to prevent the installation from 
completing if libltdl.dylib didn't get built, we were able to work out that the 
common thread was the presence of a fortran compiler. Some users had a fortran 
compiler installed at /usr/bin/gfortran; others had /usr/bin/g77 or /bin/f77. 
While we find it an error for any 3rd-party package to have installed files in 
those locations, since those are system directories, we nevertheless have the 
situation that these packages do exist, so we have to deal with them.

I'm also able to reproduce the problem by just creating a script called 
"gfortran" somewhere in the path that does nothing more than exit 1.

So the questions are:

* How do we prevent libtool from attempting to use gfortran, g77, f77, or any 
other fortran compiler, even if it's installed?

* For what reason is libtool looking for a fortran compiler at all? What does 
it use it for?

Thanks.


https://trac.macports.org/ticket/23684
https://trac.macports.org/ticket/25417
https://trac.macports.org/ticket/26908
https://trac.macports.org/ticket/30018
https://trac.macports.org/ticket/30037
https://trac.macports.org/ticket/30043
https://trac.macports.org/ticket/30105
https://trac.macports.org/ticket/30395