JupyterLite: in-browser install fails (spatialmath-python pulls in pre-commit -> packaging>=26.3) #742

Problem

The in-browser ("Try it Now" / JupyterLite) install of roboticstoolbox-python currently fails. Reproduced in real Pyodide 0.27.6 (the version bundled by the pinned jupyterlite-pyodide-kernel==0.6.1):

await micropip.install('roboticstoolbox-python')
ValueError: Requested 'packaging>=26.3', but packaging==24.2 is already installed

RTB's site installs its own wheel from the local index, but its dependencies, including spatialmath-python>=1.1.18, resolve from PyPI and hit the same error. Not verified against the deployed site; there may be a further failure after this one.

Cause

Not a change in this repo. spatialmath-python 1.1.18 lists pre-commit (a dev tool) as a runtime dependency, and pre-commit -> virtualenv 21.14.7 -> packaging>=26.3. Pyodide ships packaging 24.2 and micropip refuses to replace it. It started failing when virtualenv 21.14.7 was published.

Fix

Upstream: rai-opensource/spatialmath-python#250 moves pre-commit to the dev extra. Once a spatialmath release containing it (1.1.19) is out, no change should be needed here; re-test the install to confirm.

If waiting is not acceptable, the notebook install cell can install spatialmath-python with deps=False after installing its real dependencies explicitly (verified to work in Pyodide). MVTB did this as a temporary measure in petercorke/machinevision-toolbox-python#133.

Why CI did not catch it

There is no real-Pyodide install check here. MVTB has one (docs/lite/wasm_check/check_pyodide_install.mjs) and it is what surfaced this. Worth considering the same pattern, plus a scheduled run, because this kind of breakage arrives from PyPI with no commit in the repo.