$ git clone -n https://src.fedoraproject.org/rpms/ghc-dec.git /var/lib/mock/f38-build-side-42-init-devel-866290-28439/root/chroot_tmpdir/scmroot/ghc-dec
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-866290-28439/root/chroot_tmpdir/scmroot/ghc-dec'...
$ git fetch origin d066274b5eaf4319700e87c5cbff19c4df493ede:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-dec
 * [new ref]         d066274b5eaf4319700e87c5cbff19c4df493ede -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d066274 new boring dep