$ git clone -n https://src.fedoraproject.org/rpms/gjs.git /var/lib/mock/f39-build-2058721-49142/root/chroot_tmpdir/scmroot/gjs
Cloning into '/var/lib/mock/f39-build-2058721-49142/root/chroot_tmpdir/scmroot/gjs'...
$ git fetch origin 391685f0fd1bf92d2963ad7773b6ae82fa96a99f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gjs
 * [new ref]         391685f0fd1bf92d2963ad7773b6ae82fa96a99f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 391685f Update to 1.78.1