gfortran library not found in building demeter

[paulfons]

The demeter build fails due to the gfortran library not being found. The relevant part of the log file is shown below. I am using Xcode 11.4. I can see that the gcc9 has been properly installed and the relevant libraries are located in "/opt/local/lib/gcc9/libgfortran.a", but it appears that clang doesn't look for the gfortran library in the right location. This would appear to be a bug. I am not sure how to modify the installation procedure to explicitly add an "-L/opt/local/lib/gcc9" to the build file for macports. Any help would be appreciated as I need the underlying package.

Environment: Xcode 11.4

Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1 Apple clang version 11.0.3 (clang-1103.0.32.29) Target: x86_64-apple-darwin19.4.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

:info:build "%s", :info:build 31 warnings generated. :info:build env LD_RUN_PATH=/opt/local/lib/perl5/5.28/darwin-thread-multi-2level/CORE /usr/bin/clang -mmacosx-version-min=10.15 -bundle -undefined dynamic_lookup -L/opt/local/lib -Wl,-headerpad_max_install_names -Wl,-syslibroot,/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -fstack-protector-strong -o src/Ifeffit.dylib src/ifeffit_wrap.o -L/opt/local/lib -lifeffit -L/opt/local/lib -lpgplot -lpng -lX11 -L/opt/local/lib -L/opt/local/lib/gcc9/gcc/x86_64-apple-darwin19/9.2.0 -L/opt/local/lib/gcc9/gcc/x86_64-apple-darwin19/9.2.0/../../.. -lgfortran -lSystem -lgcc_ext.10.5 -lquadmath -lm :info:build ld: warning: directory not found for option '-L/opt/local/lib/gcc9/gcc/x86_64-apple-darwin19/9.2.0' :info:build ld: warning: directory not found for option '-L/opt/local/lib/gcc9/gcc/x86_64-apple-darwin19/9.2.0/../../..' :info:build ld: library not found for -lgfortran :info:build clang: error: linker command failed with exit code 1 (use -v to see invocation) :info:build error building src/Ifeffit.dylib from src/ifeffit_wrap.o at /opt/local/lib/perl5/5.28/ExtUtils/CBuilder/Base.pm line 332, <C> line 11. :info:build Command failed: cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_science_demeter/demeter/work/demeter-0.9.26" && ./Build install :info:build Exit code: 1 :error:build Failed to build demeter: command execution failed :debug:build Error code: CHILDSTATUS 79316 1 :debug:build Backtrace: command execution failed :debug:build while executing :debug:build "system {*}$notty {*}$nice $fullcmdstring" :debug:build invoked from within :debug:build "command_exec build" :debug:build (procedure "portbuild::build_main" line 8) :debug:build invoked from within :debug:build "$procedure $targetname" :error:build See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_science_demeter/demeter/main.log for details.