$ git clone -n https://src.fedoraproject.org/rpms/kf6-kbookmarks.git /var/lib/mock/f42-build-side-1-3503881-45982/root/chroot_tmpdir/scmroot/kf6-kbookmarks
Cloning into '/var/lib/mock/f42-build-side-1-3503881-45982/root/chroot_tmpdir/scmroot/kf6-kbookmarks'...
$ git fetch origin 52ba4c7a55b2efb3d9eeed1f9a6a70b8a7c44830:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-kbookmarks
 * [new ref]         52ba4c7a55b2efb3d9eeed1f9a6a70b8a7c44830 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 52ba4c7 6.13.0