fix(web): cross-platform sync-assets + surface build errors on failure

hermes_cli/main.py

@@ -4365,32 +4365,58 @@ def _build_web_ui(web_dir: Path, *, fatal: bool = False) -> bool:
         return True
     import shutil
 
+    # Console-encoding-safe print: Windows consoles default to cp1252
+    # (or similar) and will raise UnicodeEncodeError on arrow / check
+    # glyphs unless PYTHONIOENCODING=utf-8 is set. Routing every print
+    # in this function through _say() with errors="replace" keeps the
+    # build path usable on a stock `py -m hermes_cli.main web` invocation.
+    def _say(text: str) -> None:
+        try:
+            print(text)
+        except UnicodeEncodeError:
+            encoding = getattr(sys.stdout, "encoding", None) or "ascii"
+            print(text.encode(encoding, errors="replace").decode(encoding, errors="replace"))
+
     npm = shutil.which("npm")
     if not npm:
         if fatal:
-            print("Web UI frontend not built and npm is not available.")
-            print("Install Node.js, then run:  cd web && npm install && npm run build")
+            _say("Web UI frontend not built and npm is not available.")
+            _say("Install Node.js, then run:  cd web && npm install && npm run build")
         return not fatal
-    print("→ Building web UI...")
-    r1 = subprocess.run([npm, "install", "--silent"], cwd=web_dir, capture_output=True)
+    _say("→ Building web UI...")
+
+    def _relay(result: "subprocess.CompletedProcess") -> None:
+        """Print captured npm output so users can see *why* a step failed."""
+        for blob in (result.stdout, result.stderr):
+            if not blob:
+                continue
+            text = blob.decode("utf-8", errors="replace").rstrip() if isinstance(blob, bytes) else blob.rstrip()
+            if text:
+                _say(text)
+
+    r1 = subprocess.run(
+        [npm, "install", "--silent"], cwd=web_dir, capture_output=True
+    )
     if r1.returncode != 0:
-        print(
+        _say(
             f"  {'✗' if fatal else '⚠'} Web UI npm install failed"
             + ("" if fatal else " (hermes web will not be available)")
         )
+        _relay(r1)
         if fatal:
-            print("  Run manually:  cd web && npm install && npm run build")
+            _say("  Run manually:  cd web && npm install && npm run build")
         return False
     r2 = subprocess.run([npm, "run", "build"], cwd=web_dir, capture_output=True)
     if r2.returncode != 0:
-        print(
+        _say(
             f"  {'✗' if fatal else '⚠'} Web UI build failed"
             + ("" if fatal else " (hermes web will not be available)")
         )
+        _relay(r2)
         if fatal:
-            print("  Run manually:  cd web && npm install && npm run build")
+            _say("  Run manually:  cd web && npm install && npm run build")
         return False
-    print("  ✓ Web UI built")
+    _say("  ✓ Web UI built")
     return True
 
 

web/package.json

@@ -4,7 +4,7 @@
   "version": "0.0.0",
   "type": "module",
   "scripts": {
-    "sync-assets": "rm -rf public/fonts public/ds-assets && cp -r node_modules/@nous-research/ui/dist/fonts public/fonts && cp -r node_modules/@nous-research/ui/dist/assets public/ds-assets",
+    "sync-assets": "node scripts/sync-assets.mjs",
     "predev": "npm run sync-assets",
     "prebuild": "npm run sync-assets",
     "dev": "vite",

web/scripts/sync-assets.mjs

@@ -0,0 +1,27 @@
+#!/usr/bin/env node
+// Cross-platform replacement for the previous shell pipeline:
+//
+//   rm -rf public/fonts public/ds-assets
+//   && cp -r node_modules/@nous-research/ui/dist/fonts public/fonts
+//   && cp -r node_modules/@nous-research/ui/dist/assets public/ds-assets
+//
+// `rm -rf` / `cp -r` don't exist on Windows cmd.exe, so `npm run build`
+// (invoked from Python via subprocess → cmd.exe) failed before Vite ran.
+// Using Node's stdlib fs keeps this dependency-free and platform-neutral.
+
+import { cpSync, rmSync } from "node:fs";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const webRoot = resolve(dirname(fileURLToPath(import.meta.url)), "..");
+const uiDist = resolve(webRoot, "node_modules", "@nous-research", "ui", "dist");
+
+const targets = [
+  { from: resolve(uiDist, "fonts"), to: resolve(webRoot, "public", "fonts") },
+  { from: resolve(uiDist, "assets"), to: resolve(webRoot, "public", "ds-assets") },
+];
+
+for (const { from, to } of targets) {
+  rmSync(to, { recursive: true, force: true });
+  cpSync(from, to, { recursive: true });
+}