fix(cli): improve skill install failure output

src/agents/skills-install.ts

@@ -29,6 +29,42 @@ export type SkillInstallResult = {
   code: number | null;
 };
 
+function summarizeInstallOutput(text: string): string | undefined {
+  const raw = text.trim();
+  if (!raw) return undefined;
+  const lines = raw
+    .split("\n")
+    .map((line) => line.trim())
+    .filter(Boolean);
+  if (lines.length === 0) return undefined;
+
+  const preferred =
+    lines.find((line) => /^error\b/i.test(line)) ??
+    lines.find((line) => /\b(err!|error:|failed)\b/i.test(line)) ??
+    lines.at(-1);
+
+  if (!preferred) return undefined;
+  const normalized = preferred.replace(/\s+/g, " ").trim();
+  const maxLen = 200;
+  return normalized.length > maxLen
+    ? `${normalized.slice(0, maxLen - 1)}…`
+    : normalized;
+}
+
+function formatInstallFailureMessage(result: {
+  code: number | null;
+  stdout: string;
+  stderr: string;
+}): string {
+  const code =
+    typeof result.code === "number" ? `exit ${result.code}` : "unknown exit";
+  const summary =
+    summarizeInstallOutput(result.stderr) ??
+    summarizeInstallOutput(result.stdout);
+  if (!summary) return `Install failed (${code})`;
+  return `Install failed (${code}): ${summary}`;
+}
+
 function resolveInstallId(spec: SkillInstallSpec, index: number): string {
   return (spec.id ?? `${spec.kind}-${index}`).trim();
 }
@@ -91,7 +127,9 @@ function buildInstallCommand(
   }
 }
 
-async function resolveBrewBinDir(timeoutMs: number): Promise<string | undefined> {
+async function resolveBrewBinDir(
+  timeoutMs: number,
+): Promise<string | undefined> {
   if (!hasBinary("brew")) return undefined;
   const prefixResult = await runCommandWithTimeout(["brew", "--prefix"], {
     timeoutMs: Math.min(timeoutMs, 30_000),
@@ -204,9 +242,12 @@ export async function installSkill(
 
   if (spec.kind === "go" && !hasBinary("go")) {
     if (hasBinary("brew")) {
-      const brewResult = await runCommandWithTimeout(["brew", "install", "go"], {
-        timeoutMs,
-      });
+      const brewResult = await runCommandWithTimeout(
+        ["brew", "install", "go"],
+        {
+          timeoutMs,
+        },
+      );
       if (brewResult.code !== 0) {
         return {
           ok: false,
@@ -252,7 +293,7 @@ export async function installSkill(
   const success = result.code === 0;
   return {
     ok: success,
-    message: success ? "Installed" : "Install failed",
+    message: success ? "Installed" : formatInstallFailureMessage(result),
     stdout: result.stdout.trim(),
     stderr: result.stderr.trim(),
     code: result.code,

src/commands/onboard-skills.ts

@@ -13,6 +13,15 @@ import type { ClawdisConfig } from "../config/config.js";
 import type { RuntimeEnv } from "../runtime.js";
 import { guardCancel, resolveNodeManagerOptions } from "./onboard-helpers.js";
 
+function summarizeInstallFailure(message: string): string | undefined {
+  const cleaned = message
+    .replace(/^Install failed(?:\s*\([^)]*\))?\s*:?\s*/i, "")
+    .trim();
+  if (!cleaned) return undefined;
+  const maxLen = 140;
+  return cleaned.length > maxLen ? `${cleaned.slice(0, maxLen - 1)}…` : cleaned;
+}
+
 function upsertSkillEntry(
   cfg: ClawdisConfig,
   skillKey: string,
@@ -108,9 +117,19 @@ export async function setupSkills(
         installId,
         config: next,
       });
-      spin.stop(result.ok ? `Installed ${name}` : `Install failed: ${name}`);
-      if (!result.ok && result.stderr) {
-        runtime.log(result.stderr.trim());
+      if (result.ok) {
+        spin.stop(`Installed ${name}`);
+      } else {
+        const code = result.code == null ? "" : ` (exit ${result.code})`;
+        const detail = summarizeInstallFailure(result.message);
+        spin.stop(
+          `Install failed: ${name}${code}${detail ? ` — ${detail}` : ""}`,
+        );
+        if (result.stderr) runtime.log(result.stderr.trim());
+        else if (result.stdout) runtime.log(result.stdout.trim());
+        runtime.log(
+          "Tip: run `clawdis doctor` to review skills + requirements.",
+        );
       }
     }
   }