$ git clone -n https://src.fedoraproject.org/rpms/torbrowser-launcher.git /var/lib/mock/f40-build-2309490-57353/root/chroot_tmpdir/scmroot/torbrowser-launcher
Cloning into '/var/lib/mock/f40-build-2309490-57353/root/chroot_tmpdir/scmroot/torbrowser-launcher'...
$ git fetch origin 740d9a8509b72c1673f2365f18347a83ce04e9dd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/torbrowser-launcher
 * [new ref]         740d9a8509b72c1673f2365f18347a83ce04e9dd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 740d9a8 BR fixes