$ git clone -n https://src.fedoraproject.org/rpms/dnf-plugin-diff.git /var/lib/mock/f42-build-3528282-46309/root/chroot_tmpdir/scmroot/dnf-plugin-diff
Cloning into '/var/lib/mock/f42-build-3528282-46309/root/chroot_tmpdir/scmroot/dnf-plugin-diff'...
$ git fetch origin 1fa4395b4a0a4488061e76e0368cf759e340e19d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dnf-plugin-diff
 * [new ref]         1fa4395b4a0a4488061e76e0368cf759e340e19d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1fa4395 New upstream release (DNF5 support)