@ruzgarmax OK, I think I know what's going on. Previously Geany was launched using a bash script so it inherited all the environment variables defined in a bash config file. This isn't the case any more. Geany launches all the build commands using /bin/sh which is different than /bin/bash on macOS and it doesn't read the bash config files. Try setting the PATH to fortran inside `~/.profile` (right now it's probably set inside `~/.bashrc` or `~/.bash_profile`).
It's a little stupid Geany uses the hard-coded `/bin/sh` inside build.c. Any objections if I make this configurable inside the Various section and make it default to `/bin/bash` for macOS?