$ git clone -n https://src.fedoraproject.org/rpms/picard.git /var/lib/mock/f42-build-side-1-3499818-45966/root/chroot_tmpdir/scmroot/picard
Cloning into '/var/lib/mock/f42-build-side-1-3499818-45966/root/chroot_tmpdir/scmroot/picard'...
$ git fetch origin ee7539759f4568801bdc3c820015a3820f970f13:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/picard
 * [new ref]         ee7539759f4568801bdc3c820015a3820f970f13 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ee75397 rhbz#2346105