$ git clone -n https://src.fedoraproject.org/rpms/ghc-stm-chans.git /var/lib/mock/f38-build-side-42-init-devel-890941-28536/root/chroot_tmpdir/scmroot/ghc-stm-chans
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-890941-28536/root/chroot_tmpdir/scmroot/ghc-stm-chans'...
$ git fetch origin d01e4aebc8408d23071bc218bfb54adcb0c201a8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-stm-chans
 * [new ref]         d01e4aebc8408d23071bc218bfb54adcb0c201a8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d01e4ae Convert to %autorelease and %autochangelog