$ git clone -n https://src.fedoraproject.org/rpms/plasma-desktop.git /var/lib/mock/f40-build-2476632-61589/root/chroot_tmpdir/scmroot/plasma-desktop
Cloning into '/var/lib/mock/f40-build-2476632-61589/root/chroot_tmpdir/scmroot/plasma-desktop'...
$ git fetch origin f5bb721c393a021aa9c5599a1f6303eedf376727:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-desktop
 * [new ref]         f5bb721c393a021aa9c5599a1f6303eedf376727 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f5bb721 minor BR fixes