fix(#786): dump-manifests --manifests-dir missing-value errors now return typed missing_flag_value kind + non-null hint

ROADMAP.md

@@ -7737,3 +7737,5 @@ Original filing (2026-04-18): the session emitted `SessionStart hook (completed)
 784. **`claw export` had two opaque arg-error paths returning `error_kind:"unknown"` + `hint:null`** — dogfooded 2026-05-27 on `81fe0ccb` (pinpoint by Gaebal-gajae). `claw export --output` (missing flag value) emitted plain `"missing value for --output"` with no typed prefix; `claw export a.md b.md` (extra positional) emitted plain `"unexpected export argument: second.md"`. Both classified as `unknown+null`. Fix: (1) `--output` missing-value error now uses `missing_flag_value:` prefix + `\n` usage hint; (2) extra positional now uses `unexpected_extra_args:` prefix + `\n` usage hint; (3) classifier `unexpected_extra_args` arm extended to match both `starts_with("unexpected extra arguments")` (prose form, #766) and `starts_with("unexpected_extra_args:")` (typed prefix form, #784). Integration test `export_arg_errors_have_typed_kind_and_hint_784` covers both paths. 43 CLI contract tests pass. [SCOPE: claw-code] Source: Gaebal-gajae pinpoint + Jobdori implementation on `81fe0ccb`, 2026-05-27.
 
 785. **`claw dump` (typo/near-miss for dump-manifests) returned `error_kind:"unknown"` — no classifier arm for `"unknown subcommand:"` prose prefix** — dogfooded 2026-05-27 on `e628b4bb`. Any unknown top-level subcommand that triggers the suggestion path emitted `"unknown subcommand: <x>.\nDid you mean <y>"` but `classify_error_kind` had no arm for that prefix; all fell to the `"unknown"` catch-all. The hint was non-null (the suggestion text was extracted by `split_error_hint`) but `error_kind` was undifferentiated. Fix: added `starts_with("unknown subcommand:")` → `"unknown_subcommand"` arm. Unit test assertion + integration test `unknown_subcommand_returns_typed_kind_785` using `claw dump` as the trigger. 44 CLI contract tests pass. [SCOPE: claw-code] Source: Jobdori subcommand-classifier probe on `e628b4bb`, 2026-05-27.
+
+786. **`claw dump-manifests --manifests-dir` (missing value) and `--manifests-dir=` (empty) both returned `error_kind:"unknown"` + `hint:null`** — dogfooded 2026-05-27 on `87f43347` (pinpoint by Gaebal-gajae). Both missing `--manifests-dir` branches in `parse_dump_manifests_args` emitted plain `"--manifests-dir requires a path"` with no typed prefix; `classify_error_kind` had no matching arm so they fell to `"unknown"`. Fix: both branches now use `missing_flag_value:` prefix + `\n` usage hint. Integration test `dump_manifests_missing_dir_has_typed_kind_and_hint_786` covers both cases. 45 CLI contract tests pass. [SCOPE: claw-code] Source: Gaebal-gajae pinpoint + Jobdori implementation on `87f43347`, 2026-05-27.

rust/crates/rusty-claude-cli/src/main.rs

@@ -2159,14 +2159,15 @@ fn parse_dump_manifests_args(
         if arg == "--manifests-dir" {
             let value = args
                 .get(index + 1)
-                .ok_or_else(|| String::from("--manifests-dir requires a path"))?;
+                .ok_or_else(|| String::from("missing_flag_value: --manifests-dir requires a path.\nUsage: claw dump-manifests --manifests-dir <path> [--output-format json]"))?;
             manifests_dir = Some(PathBuf::from(value));
             index += 2;
             continue;
         }
         if let Some(value) = arg.strip_prefix("--manifests-dir=") {
             if value.is_empty() {
-                return Err(String::from("--manifests-dir requires a path"));
+                // #786: empty --manifests-dir= is also a missing value
+                return Err(String::from("missing_flag_value: --manifests-dir requires a path.\nUsage: claw dump-manifests --manifests-dir <path> [--output-format json]"));
             }
             manifests_dir = Some(PathBuf::from(value));
             index += 1;

rust/crates/rusty-claude-cli/tests/output_format_contract.rs

@@ -2537,3 +2537,78 @@ fn unknown_subcommand_returns_typed_kind_785() {
         "hint should reference the suggested subcommand or help, got: {hint:?}"
     );
 }
+
+#[test]
+fn dump_manifests_missing_dir_has_typed_kind_and_hint_786() {
+    // #786: `claw dump-manifests --manifests-dir` (no value) and `--manifests-dir=` (empty)
+    // both emitted plain "--manifests-dir requires a path" with error_kind:"unknown" + hint:null.
+    // Fix: use missing_flag_value: prefix + \n usage hint.
+    let root = unique_temp_dir("dump-manifests-missing-dir-786");
+    fs::create_dir_all(&root).expect("temp dir");
+    std::process::Command::new("git")
+        .args(["init", "-q"])
+        .current_dir(&root)
+        .output()
+        .ok();
+
+    // Case 1: --manifests-dir with no following value (next arg is --output-format)
+    let out1 = run_claw(
+        &root,
+        &[
+            "--output-format",
+            "json",
+            "dump-manifests",
+            "--manifests-dir",
+            "--output-format",
+            "json",
+        ],
+        &[],
+    );
+    assert!(!out1.status.success());
+    let stderr1 = String::from_utf8_lossy(&out1.stderr);
+    let j1: serde_json::Value = stderr1
+        .lines()
+        .find(|l| l.trim_start().starts_with('{'))
+        .and_then(|l| serde_json::from_str(l).ok())
+        .expect("missing --manifests-dir value should emit JSON error");
+    assert_eq!(
+        j1["error_kind"], "missing_flag_value",
+        "missing --manifests-dir value should be missing_flag_value, got {:?}",
+        j1["error_kind"]
+    );
+    let h1 = j1["hint"]
+        .as_str()
+        .expect("missing_flag_value must have hint (#786)");
+    assert!(
+        h1.contains("dump-manifests") || h1.contains("manifests-dir"),
+        "hint should reference dump-manifests usage, got: {h1:?}"
+    );
+
+    // Case 2: --manifests-dir= with empty value
+    let out2 = run_claw(
+        &root,
+        &[
+            "--output-format",
+            "json",
+            "dump-manifests",
+            "--manifests-dir=",
+        ],
+        &[],
+    );
+    assert!(!out2.status.success());
+    let stderr2 = String::from_utf8_lossy(&out2.stderr);
+    let j2: serde_json::Value = stderr2
+        .lines()
+        .find(|l| l.trim_start().starts_with('{'))
+        .and_then(|l| serde_json::from_str(l).ok())
+        .expect("empty --manifests-dir= should emit JSON error");
+    assert_eq!(
+        j2["error_kind"], "missing_flag_value",
+        "empty --manifests-dir= should be missing_flag_value, got {:?}",
+        j2["error_kind"]
+    );
+    let h2 = j2["hint"]
+        .as_str()
+        .expect("missing_flag_value must have hint (#786)");
+    assert!(!h2.is_empty(), "hint must not be empty");
+}