$ git clone -n https://src.fedoraproject.org/rpms/firefox.git /var/lib/mock/f38-build-729419-101806/root/chroot_tmpdir/scmroot/firefox
Cloning into '/var/lib/mock/f38-build-729419-101806/root/chroot_tmpdir/scmroot/firefox'...
$ git reset --hard 4dc43e7ccf2457afa3248e5c3927b8176841db13
HEAD is now at 4dc43e7 Disabled LTO due to rhbz#2218885