DOC: Validate versions.json before building docs #61573

Author: iabhi4

web/pandas/versions.json

@@ -49,5 +49,5 @@
         "name": "1.0",
         "version": "1.0",
         "url": "https://pandas.pydata.org/pandas-docs/version/1.0/"
-    }
+    },
 ]

web/pandas_web.py

@@ -495,4 +495,15 @@ def main(
         "--target-path", default="build", help="directory where to write the output"
     )
     args = parser.parse_args()
+
+    # Sanity check: validate that versions.json is valid JSON
+    versions_path = os.path.join(args.source_path, "versions.json")
+    if os.path.exists(versions_path):
+        try:
+            with open(versions_path, encoding="utf-8") as f:
+                json.load(f)
+        except json.JSONDecodeError as e:
+            sys.stderr.write(f"\n[ERROR] Invalid JSON in {versions_path}:\n{e}\n")
+            sys.exit(1)
+
     sys.exit(main(args.source_path, args.target_path))