pyemscripten wheel is unimportable: the Python layer imports async-only classes unconditionally

[m-albert]

Just stumbled upon this and wanted to quickly report 🙏

import zarrista fails on Pyodide with the published zarrista-0.1.0-cp314-cp314-pyemscripten_2026_0_wasm32.whl.

Reproducer

Pyodide 314.0.4, Node 26, zarrista 0.1.0:

import { loadPyodide } from "pyodide";

const pyodide = await loadPyodide({ packages: ["micropip"] });
await pyodide.runPythonAsync(`
import micropip
# see the footnote: zarr-metadata 0.5.0 wants typing-extensions>=4.16, Pyodide ships 4.15.0
await micropip.install(["typing-extensions>=4.16"], reinstall=True)
await micropip.install(["zarrista"])
import zarrista
`);

zarr-metadata 0.5.0 requires typing-extensions>=4.16, while Pyodide 314 ships 4.15.0, so micropip refuses to install zarrista at all.

[kylebarron]

Thanks for the bug report.

I'd be happy to add a test to CI to validate that emscripten can import the module without errors. Is it as simple as what you pasted there?