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MW003: incompatible-package

🌐 WASM ❌ Not Fixable

MW003: Packages in the dependency tree incompatible with WASM.

What it does

Reads the notebook's PEP 723 dependencies, walks their transitive dependency tree via installed metadata, then queries PyPI's JSON API to check whether each package has a py3-none-any or emscripten wheel available. Packages only in pyodide-lock.json are also accepted.

Why is this bad?

Pyodide can only install pure-Python wheels via micropip, or packages that are pre-built in the Pyodide distribution. Packages with only platform-specific native wheels will fail to install in the browser.

Examples

Problematic: 

import jax  # jaxlib (transitive dep) has only native wheels

Not flagged: 

import numpy  # Native, but pre-built in Pyodide

Not flagged: 

import requests  # Pure Python wheel on PyPI

References