$ git clone -n https://src.fedoraproject.org/rpms/cosmic-idle.git /var/lib/mock/f41-build-side-1-3121225-39465/root/chroot_tmpdir/scmroot/cosmic-idle
Cloning into '/var/lib/mock/f41-build-side-1-3121225-39465/root/chroot_tmpdir/scmroot/cosmic-idle'...
$ git fetch origin 190a289396ac45f18c8ec787ef74655ab27fec69:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cosmic-idle
 * [new ref]         190a289396ac45f18c8ec787ef74655ab27fec69 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 190a289 "Update to 1.0.0~alpha.3"