$ git clone -n https://src.fedoraproject.org/rpms/bcm283x-firmware.git /var/lib/mock/f41-build-856561-167674/root/chroot_tmpdir/scmroot/bcm283x-firmware
Cloning into '/var/lib/mock/f41-build-856561-167674/root/chroot_tmpdir/scmroot/bcm283x-firmware'...
$ git fetch origin 8b81117b673d26dc43fe6efdff98567f0531e346:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bcm283x-firmware
 * [new ref]         8b81117b673d26dc43fe6efdff98567f0531e346 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8b81117 Update to 48cd9f9