$ git clone -n https://src.fedoraproject.org/rpms/kBuild.git /var/lib/mock/f40-build-2199607-51750/root/chroot_tmpdir/scmroot/kBuild
Cloning into '/var/lib/mock/f40-build-2199607-51750/root/chroot_tmpdir/scmroot/kBuild'...
$ git fetch origin 8f7fd123fb8352ffa555a6b3d2d8777c0c031a74:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kBuild
 * [new ref]         8f7fd123fb8352ffa555a6b3d2d8777c0c031a74 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8f7fd12 Fix another C compatibility issue (#2154544)