diff --git a/pyscript.core/package-lock.json b/pyscript.core/package-lock.json
index f50a610a..1eae2889 100644
--- a/pyscript.core/package-lock.json
+++ b/pyscript.core/package-lock.json
@@ -33,6 +33,7 @@
                 "@xterm/addon-web-links": "^0.11.0",
                 "bun": "^1.1.27",
                 "chokidar": "^4.0.0",
+                "codedent": "^0.1.2",
                 "codemirror": "^6.0.1",
                 "eslint": "^9.10.0",
                 "flatted": "^3.3.1",
diff --git a/pyscript.core/package.json b/pyscript.core/package.json
index bf255e62..2d9c7e12 100644
--- a/pyscript.core/package.json
+++ b/pyscript.core/package.json
@@ -79,6 +79,7 @@
         "@xterm/addon-web-links": "^0.11.0",
         "bun": "^1.1.27",
         "chokidar": "^4.0.0",
+        "codedent": "^0.1.2",
         "codemirror": "^6.0.1",
         "eslint": "^9.10.0",
         "flatted": "^3.3.1",
diff --git a/pyscript.core/rollup/stdlib.cjs b/pyscript.core/rollup/stdlib.cjs
index 995a08b7..9009cbdc 100644
--- a/pyscript.core/rollup/stdlib.cjs
+++ b/pyscript.core/rollup/stdlib.cjs
@@ -9,20 +9,43 @@ const { spawnSync } = require("node:child_process");
 
 const { join } = require("node:path");
 
+const dedent = require("codedent");
+
 const crawl = (path, json) => {
     for (const file of readdirSync(path)) {
         const full = join(path, file);
         if (/\.py$/.test(file)) {
             if (process.env.NO_MIN) json[file] = readFileSync(full).toString();
             else {
-                const {
-                    output: [error, result],
-                } = spawnSync("pyminify", [
-                    "--remove-literal-statements",
-                    full,
-                ]);
-                if (error) process.exit(1);
-                json[file] = result.toString();
+                try {
+                    const {
+                        output: [error, result],
+                    } = spawnSync("pyminify", [
+                        "--remove-literal-statements",
+                        full,
+                    ]);
+                    if (error) {
+                        console.error(error);
+                        process.exit(1);
+                    }
+                    json[file] = result.toString();
+                } catch (error) {
+                    console.error(error);
+                    console.log(
+                        dedent(`
+                            \x1b[1m⚠️  is your env activated?\x1b[0m
+                            \x1b[2mYou need a Python env to run \x1b[0mpyminify\x1b[2m.\x1b[0m
+                            \x1b[2mTo do so, you can try the following:\x1b[0m
+                            python -m venv env
+                            source env/bin/activate
+                            pip install --upgrade pip
+                            pip install --ignore-requires-python python-minifier
+                            pip install setuptools
+                            \x1b[2mand you can then try \x1b[0mnpm run build\x1b[2m again.\x1b[0m
+                        `),
+                    );
+                    process.exit(1);
+                }
             }
         } else if (statSync(full).isDirectory() && !file.endsWith("_"))
             crawl(full, (json[file] = {}));