This check got inverted during the work on "Worker errors backwards
compatibility". As a consequence, osbuild was never run and the
result structure `buildResult.OSBuildOutput` was `nil` Since the
overall status reporting is not complete, and does not take this,
i.e. `buildResult.OSBuildOutput`, being `nil` as an error case,
the overall status was reported as "success". See the function
`composeStatusFromJobStatus` in `internal/kojiapi/server.go`.