dx: Include path count in export error message (#89333)

Supersedes #88910

---
<a
href="https://cursor.com/background-agent?bcId=bc-a05c69b9-7049-4095-8985-761868c63e1c"><picture><source
media="(prefers-color-scheme: dark)"
srcset="https://cursor.com/assets/images/open-in-cursor-dark.png"><source
media="(prefers-color-scheme: light)"
srcset="https://cursor.com/assets/images/open-in-cursor-light.png"><img
alt="Open in Cursor" width="131" height="28"
src="https://cursor.com/assets/images/open-in-cursor-dark.png"></picture></a>&nbsp;<a
href="https://cursor.com/agents?id=bc-a05c69b9-7049-4095-8985-761868c63e1c"><picture><source
media="(prefers-color-scheme: dark)"
srcset="https://cursor.com/assets/images/open-in-web-dark.png"><source
media="(prefers-color-scheme: light)"
srcset="https://cursor.com/assets/images/open-in-web-light.png"><img
alt="Open in Web" width="114" height="28"
src="https://cursor.com/assets/images/open-in-web-dark.png"></picture></a>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Sebastian "Sebbie" Silbermann <sebastian.silbermann@vercel.com>

Author: 3 people

packages/next/errors.json

@@ -1050,5 +1050,6 @@
   "1049": "Turbopack is not supported on this platform (%s/%s) because native bindings are not available. Only WebAssembly (WASM) bindings were loaded, and Turbopack requires native bindings.\\n\\nTo use Next.js on this platform, use Webpack instead:\\n  next dev --webpack\\n\\nFor more information, see: https://nextjs.org/docs/app/api-reference/turbopack#supported-platforms",
   "1050": "Turbopack is not supported on this platform (%s/%s) because native bindings are not available. Only WebAssembly (WASM) bindings were loaded, and Turbopack requires native bindings.\\n\\nTo build on this platform, use Webpack instead:\\n  next build --webpack\\n\\nFor more information, see: https://nextjs.org/docs/app/api-reference/turbopack#supported-platforms",
   "1051": "Turbopack trace server is not supported on this platform (%s/%s) because native bindings are not available. Only WebAssembly (WASM) bindings were loaded, and Turbopack requires native bindings.",
-  "1052": "Turbopack is not supported on this platform (%s/%s) because native bindings are not available. Only WebAssembly (WASM) bindings were loaded, and Turbopack requires native bindings. Use the --webpack flag instead."
+  "1052": "Turbopack is not supported on this platform (%s/%s) because native bindings are not available. Only WebAssembly (WASM) bindings were loaded, and Turbopack requires native bindings. Use the --webpack flag instead.",
+  "1053": "Export encountered errors on %s %s:\\n\\t%s"
 }

packages/next/src/export/index.ts

@@ -997,7 +997,7 @@ async function exportAppImpl(
   if (failedExportAttemptsByPage.size > 0) {
     const failedPages = Array.from(failedExportAttemptsByPage.keys())
     throw new ExportError(
-      `Export encountered errors on following paths:\n\t${failedPages
+      `Export encountered errors on ${failedPages.length} ${failedPages.length === 1 ? 'path' : 'paths'}:\n\t${failedPages
         .sort()
         .join('\n\t')}`
     )