$ git clone -n https://src.fedoraproject.org/rpms/kblackbox.git /var/lib/mock/f40-build-2241429-53664/root/chroot_tmpdir/scmroot/kblackbox
Cloning into '/var/lib/mock/f40-build-2241429-53664/root/chroot_tmpdir/scmroot/kblackbox'...
$ git fetch origin 88402520e4d95b0f66b1f73397152617e42654a0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kblackbox
 * [new ref]         88402520e4d95b0f66b1f73397152617e42654a0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8840252 24.01.90