$ git clone -n https://src.fedoraproject.org/rpms/firecracker.git /var/lib/mock/f40-build-2633344-65937/root/chroot_tmpdir/scmroot/firecracker
Cloning into '/var/lib/mock/f40-build-2633344-65937/root/chroot_tmpdir/scmroot/firecracker'...
$ git fetch origin 6ce8598c7c0e3b2a6bb6752943542384ada096cd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/firecracker
 * [new ref]         6ce8598c7c0e3b2a6bb6752943542384ada096cd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6ce8598 Update to version 1.7.0