$ git clone -n https://src.fedoraproject.org/rpms/plasma-desktop.git /var/lib/mock/f40-build-781266-131566/root/chroot_tmpdir/scmroot/plasma-desktop
Cloning into '/var/lib/mock/f40-build-781266-131566/root/chroot_tmpdir/scmroot/plasma-desktop'...
$ git fetch origin 1b2a187ebde4769da512b47bc7246e885fc4b0b7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-desktop
 * [new ref]         1b2a187ebde4769da512b47bc7246e885fc4b0b7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1b2a187 6.0.0