$ git clone -n https://src.fedoraproject.org/rpms/frr.git /var/lib/mock/f42-build-side-1-3502605-45978/root/chroot_tmpdir/scmroot/frr
Cloning into '/var/lib/mock/f42-build-side-1-3502605-45978/root/chroot_tmpdir/scmroot/frr'...
$ git fetch origin e6b9b78718a2325ff216be56d47fe2ce660d4d66:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/frr
 * [new ref]         e6b9b78718a2325ff216be56d47fe2ce660d4d66 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e6b9b78 Add explicit BR: libxcrypt-devel