$ git clone -n https://src.fedoraproject.org/rpms/kf6-kunitconversion.git /var/lib/mock/f42-build-side-1-3501278-45974/root/chroot_tmpdir/scmroot/kf6-kunitconversion
Cloning into '/var/lib/mock/f42-build-side-1-3501278-45974/root/chroot_tmpdir/scmroot/kf6-kunitconversion'...
$ git fetch origin b729279f847ee0c689b5bdca84cd8cb2e6e99a0a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-kunitconversion
 * [new ref]         b729279f847ee0c689b5bdca84cd8cb2e6e99a0a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b729279 6.13.0