$ git clone -n https://src.fedoraproject.org/rpms/cosmic-greeter.git /var/lib/mock/f41-build-side-1-3110240-39405/root/chroot_tmpdir/scmroot/cosmic-greeter
Cloning into '/var/lib/mock/f41-build-side-1-3110240-39405/root/chroot_tmpdir/scmroot/cosmic-greeter'...
$ git fetch origin ce3548ceb62a2747475480ef9db378944287dbba:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cosmic-greeter
 * [new ref]         ce3548ceb62a2747475480ef9db378944287dbba -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ce3548c "Update to 1.0.0~alpha.3"