$ git clone -n https://src.fedoraproject.org/forks/packit/rpms/image-builder.git /var/lib/mock/f41-build-61075014-6588571/root/chroot_tmpdir/scmroot/image-builder
Cloning into '/var/lib/mock/f41-build-61075014-6588571/root/chroot_tmpdir/scmroot/image-builder'...
$ git fetch origin 286937c7cb5e6762d90a379686ea4ed1a19d78ee:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/forks/packit/rpms/image-builder
 * [new ref]         286937c7cb5e6762d90a379686ea4ed1a19d78ee -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 286937c Update to 25 upstream release