pyscript · WebReflection · Nov 4, 2025
diff --git a/docs/index.js b/docs/index.js
diff --git a/docs/index.js.map b/docs/index.js.map
diff --git a/esm/interpreter/pyodide.js b/esm/interpreter/pyodide.js
@@ -8,7 +8,7 @@ const type = 'pyodide';
 const toJsOptions = { dict_converter: Object.fromEntries };
 
 const { stringify } = JSON;
-const { hasOwn } = Object;
+const { hasOwn, keys } = Object;
 
 const { apply } = Reflect;
 const FunctionPrototype = Function.prototype;
@@ -66,6 +66,8 @@ const override = intercept => {
     });
 };
 
+const warnOnPackageVersion = (version, name, value) => console.warn(`Pyodide ${version} might not support package ${name} version ${value}`);
+
 const progress = createProgress('py');
 const indexURLs = new WeakMap();
 
@@ -88,8 +90,29 @@ export default {
                         if (/^https?:\/\//.test(entry)) return false;
                         const [name, ...rest] = entry.split(/[>=<]=/);
                         const known = hasOwn(graph[version], name);
-                        return !known || (rest.length > 0 && rest[0] !== graph[version][name]);
+                        if (!known) {
+                            // check if the package is available in the graph
+                            // with a different version that could work: warning only
+                            for (const key of keys(graph)) {
+                                if (key !== version && hasOwn(graph[key], name)) {
+                                    warnOnPackageVersion(version, name, rest.at(0) ?? graph[key][name]);
+                                    return false;
+                                }
+                            }
+                            // package not available in the graph with any version: error
+                            return true;
+                        }
+                        // warn if the pinned version is different from the one in the graph
+                        if (rest.length > 0 && rest[0] !== graph[version][name]) {
+                            warnOnPackageVersion(version, name, rest[0]);
+                        }
+                        // if known and pinned? it's considered valid
+                        return false;
                     });
+
+                    // invalid packages should not be allowed though
+                    // use a different index_url if needed because Pyodide
+                    // clearly never stated such package could work
                     if (invalid.length > 0) {
                         throw new Error(
                             `These packages are not supported in Pyodide ${version}: ${invalid.join(', ')}`

diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -53,7 +53,7 @@
         "@zip.js/zip.js": "^2.8.8",
         "c8": "^10.1.3",
         "chokidar": "^4.0.3",
-        "eslint": "^9.38.0",
+        "eslint": "^9.39.1",
         "linkedom": "^0.18.12",
         "rollup": "^4.52.5",
         "static-handler": "^0.5.3",
@@ -95,6 +95,6 @@
         "to-json-callback": "^0.1.1"
     },
     "worker": {
-        "blob": "sha256-Epkjn7aMtcD7+5b5zqBH2CMgCLalXtFSWfuOZ7eOVCg="
+        "blob": "sha256-lqTEoZcle8/LL85zi+N9VbMxe3g75m8m/cQ+pT+a0nI="
     }
 }
diff --git a/test/pygame-ce/config.toml b/test/pygame-ce/config.toml
@@ -0,0 +1 @@
+packages = ["pygame-ce==2.4.1"]
diff --git a/test/pygame-ce/index.html b/test/pygame-ce/index.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <title>PyScript 0.28 warning on pygame-ce</title>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width,initial-scale=1">
+    <script type="module" src="../../dist/index.js"></script>
+</head>
+<body>
+  <script type="pyodide" version="0.28.0" config="config.toml">
+    from js import document
+    document.body.append("OK")
+  </script>
+</body>
+</html>