Repository: electron/electron
Pull request: build: improve `check-zip-manifest`

#### Description of Change

Refs https://github.com/electron/electron/pull/47747/commits/05f3c4cfa055d656a0ff37170e24751a5be263b0

Improve output from zip manifest check to make it clearer what action needs to be taken and what the error was.

#### Checklist
<!-- Remove items that do not apply. For completed items, change [ ] to [x]. -->

- [x] PR description included and stakeholders cc'd
- [x] `npm test` passes
- [x] [PR release notes](https://github.com/electron/clerk/blob/main/README.md) describe the change in a way relevant to app developers, and are [capitalized, punctuated, and past tense](https://github.com/electron/clerk/blob/main/README.md#examples).

#### Release Notes

Notes: none


Changed files:
filename: script/zip_manifests/check-zip-manifest.py
patch: @@ -2,24 +2,79 @@
 
 import zipfile
 import sys
+import os
 
-def main(zip_path, manifest_in):
-  with open(manifest_in, 'r', encoding='utf-8') as manifest, \
-      zipfile.ZipFile(zip_path, 'r', allowZip64=True) as z:
-    files_in_zip = set(z.namelist())
-    files_in_manifest = {l.strip() for l in manifest.readlines()}
-  added_files = files_in_zip - files_in_manifest
-  removed_files = files_in_manifest - files_in_zip
-  if added_files:
-    print("Files added to bundle:")
-    for f in sorted(list(added_files)):
-      print('+' + f)
-  if removed_files:
-    print("Files removed from bundle:")
-    for f in sorted(list(removed_files)):
-      print('-' + f)
-
-  return 1 if added_files or removed_files else 0
+def main(zip_path, manifest_path):
+    """
+    Compare a zip file's contents against a manifest file.
+    Returns 0 if they match, 1 if there are differences.
+    """
+
+    if not os.path.exists(zip_path):
+        print(f"ERROR: Zip file not found: {zip_path}", file=sys.stderr)
+        return 1
+
+    if not os.path.exists(manifest_path):
+        print(f"ERROR: Manifest file not found: {manifest_path}", file=sys.stderr)
+        return 1
+
+    try:
+        with zipfile.ZipFile(zip_path, 'r', allowZip64=True) as z:
+            files_in_zip = set(z.namelist())
+    except zipfile.BadZipFile:
+        print(f"ERROR: Invalid zip file: {zip_path}", file=sys.stderr)
+        return 1
+    except Exception as e:
+        print(f"ERROR: Failed to read zip file {zip_path}: {e}", file=sys.stderr)
+        return 1
+
+    try:
+        with open(manifest_path, 'r', encoding='utf-8') as manifest:
+            files_in_manifest = {line.strip() for line in manifest.readlines() if line.strip()}
+    except Exception as e:
+        print(f"ERROR: Failed to read manifest file {manifest_path}: {e}", file=sys.stderr)
+        return 1
+
+    added_files = files_in_zip - files_in_manifest
+    removed_files = files_in_manifest - files_in_zip
+
+    if not added_files and not removed_files:
+        print("OK: Zip contents match manifest - no differences found")
+        return 0
+
+    print("ERROR: Zip contents do not match manifest!")
+    print(f"Zip file: {zip_path}")
+    print(f"Manifest: {manifest_path}")
+    print()
+
+    if added_files:
+        print(f"Files in zip but NOT in manifest ({len(added_files)} files):")
+        for f in sorted(added_files):
+            print(f"  + {f}")
+        print()
+
+    if removed_files:
+        print(f"Files in manifest but NOT in zip ({len(removed_files)} files):")
+        for f in sorted(removed_files):
+            print(f"  - {f}")
+        print()
+
+    print("ACTION REQUIRED:")
+    if added_files:
+        print("- Add the new files to the manifest, or")
+        print("- Remove them from the zip if they shouldn't be included")
+    if removed_files:
+        print("- Remove the missing files from the manifest, or")
+        print("- Add them to the zip if they should be included")
+
+    return 1
 
 if __name__ == '__main__':
-  sys.exit(main(sys.argv[1], sys.argv[2]))
+    if len(sys.argv) != 3:
+        print("Usage: check-zip-manifest.py <zip_file> <manifest_file>", file=sys.stderr)
+        print("", file=sys.stderr)
+        print("Compares the contents of a zip file against a manifest file.", file=sys.stderr)
+        print("Returns 0 if they match, 1 if there are differences or errors.", file=sys.stderr)
+        sys.exit(1)
+
+    sys.exit(main(sys.argv[1], sys.argv[2]))