$ git clone -n https://src.fedoraproject.org/rpms/bcm283x-firmware.git /var/lib/mock/f41-build-3150603-40566/root/chroot_tmpdir/scmroot/bcm283x-firmware
Cloning into '/var/lib/mock/f41-build-3150603-40566/root/chroot_tmpdir/scmroot/bcm283x-firmware'...
$ git fetch origin c9666eec1c0a9a1f960e6058a26e56a2add19a2f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bcm283x-firmware
 * [new ref]         c9666eec1c0a9a1f960e6058a26e56a2add19a2f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c9666ee Update to 545e5aa