windmill-labs/windmill · warning

--arg for ${p} is unused — it isn't in the run selection.

Error message

--arg for ${p} is unused — it isn't in the run selection.

What it means

In `wmill pipeline run`, a plain --arg whose target script is not in the final run selection is silently ignored, so the CLI warns per path, mirroring the --upload warning. It flags args that will never reach a step in this run.

Source

Thrown at cli/src/commands/pipeline/pipeline.ts:914

    const unresolvable = order.filter(
      (p) => partitionKindByPath.get(p) === "dynamic",
    );
    if (unresolvable.length > 0) {
      throw new Error(
        `dynamic \`// partitioned\` script(s) need an explicit partition for a local run: ${unresolvable.sort().join(", ")} — pass --partition <value>.`,
      );
    }
  }

  // A `--upload` whose script fell outside the selection is a no-op the user
  // should know about, rather than silently ignored.
  const orderSet = new Set(order);
  const boundInOrder = [...boundBindingsByPath.keys()].filter((p) => orderSet.has(p)).sort();
  for (const p of boundBindingsByPath.keys()) {
    if (!orderSet.has(p)) log.warn(`--upload for ${p} is unused — it isn't in the run selection.`);
  }
  for (const p of plainArgsByPath.keys()) {
    if (!orderSet.has(p)) log.warn(`--arg for ${p} is unused — it isn't in the run selection.`);
  }

  if (opts.json) {
    // Surface reachable/dropped ends so a machine-readable plan reflects the
    // same trimming the human-facing warning does — a resolved-but-unreachable
    // `--to` must not look like a clean plan that silently runs only the start.
    console.log(
      JSON.stringify({
        start: runAll ? null : scriptPathOf(start!),
        ends: ends.map(idLabel),
        reachableEnds: reachableEnds.map(idLabel),
        droppedEnds: droppedEnds.map(idLabel),
        order,
        cyclic,
        uploads: boundInOrder,
      }),
    );
  }

View on GitHub (pinned to e474e8803c)

Solutions

1. Widen the run selection (--start/--end, avoid cutting barriers) so the target script is included.
2. Fix the script path in --arg if it is wrong.
3. Drop the unused --arg flag.
4. Use --json to inspect the plan's selected/trimmed nodes before running.

Example fix

// before: arg target outside window
wmill pipeline run f/myflow --start a --end b --arg f/myflow/z=42
// after
wmill pipeline run f/myflow --start a --end z --arg f/myflow/z=42

// confirm every --arg target is inside the planned selection
const plan = JSON.parse(execSync('wmill pipeline run f/x --start a --end b --json').toString());
const args = ['f/myflow/z'];
const missing = args.filter(p => !plan.order.includes(p));
if (missing.length) throw new Error(`--arg targets not in selection: ${missing}`);

When it happens

Trigger: Passing --arg <path>=<value> for a script excluded by the --start/--end window, barriers, cycles, or not-runnable filtering, or with a mistyped script path.

Common situations: Reusing an old command line after narrowing the run window; arg paths not updated after scripts were renamed; args intended for steps behind a barrier.

Related errors

• --upload for ${p} is unused — it isn't in the run selection.
• end '${idLabel(d)}' is not downstream of the start — ignored
• end '${idLabel(e)}' is only reachable through a skipped inpu
• Skipping ${cyclic.length} script(s) on a dependency cycle: $
• App ${appPath} not found

AI-assisted analysis of windmill-labs/windmill@e474e8803c (2026-09-03). Data as JSON: /api/errors/dbcea78002e87a3f. Report an issue: GitHub.