Xcode12 doesn't work with Catalina. The following message is displayed if you try to run Xcode 12.5: You can’t use this version of the application “Xcode-beta.app” with this version of macOS. You have macOS 10.15.7. The application requires macOS 11.0 or later.

You are right. The following command is successful: flang-new *.f90 /System/Volumes/Data/Library/Developer/CommandLineTools/usr/lib/clang/16/lib/darwin/libclang_rt.osx.a Is there a more simple way to perform the link? I don't see this directory in the default PATH.

Flang-new works perfect on MacOS Sequoia. Faster than gfortran. Install it with Homebrew and add the following lines on .zprofile: Support for flang-new compiler export LIBRARY_PATH=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib export LIBRARY_PATH="$LIBRARY_PATH:/Library/Developer/CommandLineTools/usr/lib/clang/16/lib/darwin" export LLVMTOOLS=/opt/homebrew/Cellar/flang/19.1.6/lib # directory with libfortran.a Enjoy.