$ git clone -n https://src.fedoraproject.org/rpms/snapd.git /var/lib/mock/f42-build-3338887-41426/root/chroot_tmpdir/scmroot/snapd
Cloning into '/var/lib/mock/f42-build-3338887-41426/root/chroot_tmpdir/scmroot/snapd'...
$ git fetch origin b3caa4d90a72e33192ad5938b3a6b86ea303a308:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/snapd
 * [new ref]         b3caa4d90a72e33192ad5938b3a6b86ea303a308 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b3caa4d New upstream release 2.67