$ git clone -n https://src.fedoraproject.org/rpms/firefox.git /var/lib/mock/f37-build-666154-74317/root/chroot_tmpdir/scmroot/firefox
Cloning into '/var/lib/mock/f37-build-666154-74317/root/chroot_tmpdir/scmroot/firefox'...
$ git reset --hard c93bbf6684daad651035b4420743f5d41e8f2288
HEAD is now at c93bbf6 Build fix, disabled portals on F37+