$ git clone -n https://src.fedoraproject.org/rpms/virtualbox-guest-additions.git /var/lib/mock/f38-build-side-42-init-devel-1283189-30672/root/chroot_tmpdir/scmroot/virtualbox-guest-additions
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1283189-30672/root/chroot_tmpdir/scmroot/virtualbox-guest-additions'...
$ git fetch origin 9665c32706d822a9713277f7bc38f8f8d2ecb877:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/virtualbox-guest-additions
 * [new ref]         9665c32706d822a9713277f7bc38f8f8d2ecb877 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9665c32 Update virtualbox-guest-additions to 7.0.10 (#2223732)