Add `--warning=-unknown-keyword` as suggested https://gitlab.eclipse.org/eclipsefdn/helpdesk/-/issues/3630#note_1203399 to the tar command https://github.com/eclipse-packaging/packages/blob/d79ee79a5c4f6ae847834efd91cbad4f5c753133/releng/org.eclipse.epp.config/tools/check-incubating.sh#L11 See also https://github.com/eclipse-tycho/tycho/issues/2586 where I raised the header added in tycho.