$ git clone -n https://src.fedoraproject.org/rpms/dsda-doom.git /var/lib/mock/f42-build-side-1-3497644-45961/root/chroot_tmpdir/scmroot/dsda-doom
Cloning into '/var/lib/mock/f42-build-side-1-3497644-45961/root/chroot_tmpdir/scmroot/dsda-doom'...
$ git fetch origin eb6c339c73c75619a5a07c9415014518b33de726:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dsda-doom
 * [new ref]         eb6c339c73c75619a5a07c9415014518b33de726 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at eb6c339 Update to v0.29.0