$ git clone -n https://src.fedoraproject.org/rpms/icestorm.git /var/lib/mock/f41-build-815551-149588/root/chroot_tmpdir/scmroot/icestorm
Cloning into '/var/lib/mock/f41-build-815551-149588/root/chroot_tmpdir/scmroot/icestorm'...
$ git fetch origin f5f729ac9309c8137bc1aec4f154238cba617410:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/icestorm
 * [new ref]         f5f729ac9309c8137bc1aec4f154238cba617410 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f5f729a update to new snapshot