fix: prevent getLoadedSkills crash and auto-build workspace packages (#1767)

Add defensive fallback in auto-prompts.ts so a missing getLoadedSkills
export degrades gracefully (empty skill list) instead of crashing every
auto-mode dispatch iteration.

Add ensure-workspace-builds.cjs postinstall script that detects missing
dist/ directories in workspace packages and rebuilds them automatically.
This prevents stale-build issues after fresh clones where dist/ is
gitignored but required at runtime by jiti-loaded extensions.

Closes #1734

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -66,7 +66,7 @@
     "build:native": "node native/scripts/build.js",
     "build:native:dev": "node native/scripts/build.js --dev",
     "dev": "node scripts/dev.js",
-    "postinstall": "node scripts/link-workspace-packages.cjs && node scripts/postinstall.js",
+    "postinstall": "node scripts/link-workspace-packages.cjs && node scripts/ensure-workspace-builds.cjs && node scripts/postinstall.js",
     "pi:install-global": "node scripts/install-pi-global.js",
     "pi:uninstall-global": "node scripts/uninstall-pi-global.js",
     "sync-pkg-version": "node scripts/sync-pkg-version.cjs",

scripts/ensure-workspace-builds.cjs

@@ -0,0 +1,58 @@
+#!/usr/bin/env node
+/**
+ * ensure-workspace-builds.cjs
+ *
+ * Checks whether workspace packages have been compiled (dist/ exists with
+ * index.js). If any are missing, runs the build for those packages.
+ *
+ * Designed for the postinstall hook so that `npm install` in a fresh clone
+ * produces a working runtime without a manual `npm run build` step.
+ *
+ * Skipped in CI (where the full build pipeline handles this) and when
+ * installing as an end-user dependency (no packages/ directory).
+ */
+const { existsSync } = require('fs')
+const { resolve, join } = require('path')
+const { execSync } = require('child_process')
+
+const root = resolve(__dirname, '..')
+const packagesDir = join(root, 'packages')
+
+// Skip if packages/ doesn't exist (published tarball / end-user install)
+if (!existsSync(packagesDir)) process.exit(0)
+
+// Skip in CI — the pipeline runs `npm run build` explicitly
+if (process.env.CI === 'true' || process.env.CI === '1') process.exit(0)
+
+// Workspace packages that need dist/index.js at runtime.
+// Order matters: dependencies must build before dependents.
+const WORKSPACE_PACKAGES = [
+  'native',
+  'pi-tui',
+  'pi-ai',
+  'pi-agent-core',
+  'pi-coding-agent',
+]
+
+const missing = []
+for (const pkg of WORKSPACE_PACKAGES) {
+  const distIndex = join(packagesDir, pkg, 'dist', 'index.js')
+  if (!existsSync(distIndex)) {
+    missing.push(pkg)
+  }
+}
+
+if (missing.length === 0) process.exit(0)
+
+process.stderr.write(`  Building ${missing.length} workspace package(s) missing dist/: ${missing.join(', ')}\n`)
+
+for (const pkg of missing) {
+  const pkgDir = join(packagesDir, pkg)
+  try {
+    execSync('npm run build', { cwd: pkgDir, stdio: 'pipe' })
+    process.stderr.write(`  ✓ ${pkg}\n`)
+  } catch (err) {
+    process.stderr.write(`  ✗ ${pkg} build failed: ${err.message}\n`)
+    // Non-fatal — the user can run `npm run build` manually
+  }
+}

src/resources/extensions/gsd/auto-prompts.ts

@@ -424,7 +424,7 @@ export function buildSkillActivationBlock(params: {
     params.taskPlanContent ?? undefined,
   );
 
-  const visibleSkills = getLoadedSkills().filter(skill => !skill.disableModelInvocation);
+  const visibleSkills = (typeof getLoadedSkills === 'function' ? getLoadedSkills() : []).filter(skill => !skill.disableModelInvocation);
   const installedNames = new Set(visibleSkills.map(skill => normalizeSkillReference(skill.name)));
   const avoided = new Set(resolvePreferenceSkillNames(prefs?.avoid_skills ?? [], params.base));
   const matched = new Set<string>();