fftw-3 does not configure with +gfortran (Catalina, Xcode 10.3, Macports-2.6.1)

[nombak]

% port install fftw-3 +gfortran+openmpi
--->  Configuring fftw-3
Error: openmpi-default has a different Fortran variant () than the one selected, gcc9 (via +gfortran).
Error: Failed to configure fftw-3: Install openmpi-default +gcc9
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_www.macports.org_files_ports_math_fftw-3/fftw-3/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.
Error: Processing of port fftw-3 failed

Following the message,

% port deactivate openmpi-default
% port install openmpi-default +gcc9

Then, tried again

% port install fftw-3 +gfortran+openmpi

, which surprisingly, deactivated the newly installed "openmpi-default +gcc9" (contrary to its own message), and activated the old "openmpi-default", which resulted in the same error.

[jmroot (Joshua Root)]

You need to be using Xcode 11.x on Catalina, but there are also unresolved issues with gcc.