Improve error message when running pyodide build on an unsupported Python version #93
Description
I came across this one today.
Running pyodide build displays
───────────────────────────────────────────────────────── Traceback (most recent call last) ──────────────────────────────────────────────────────────╮
│ /Users/agriyakhetarpal/envs/skimage-dev/lib/python3.13/site-packages/pyodide_build/cli/build.py:180 in main │
│ │
│ 177 │ ctx: typer.Context = typer.Context, # type: ignore[assignment] │
│ 178 ) -> None: │
│ 179 │ """Use pypa/build to build a Python package from source, pypi or url.""" │
│ ❱ 180 │ init_environment() │
│ 181 │ try: │
│ 182 │ │ check_emscripten_version() │
│ 183 │ except RuntimeError as e: │
│ │
│ /Users/agriyakhetarpal/envs/skimage-dev/lib/python3.13/site-packages/pyodide_build/build_env.py:59 in init_environment │
│ │
│ 56 │ │
│ 57 │ root = search_pyodide_root(Path.cwd()) │
│ 58 │ if not root: # Not in Pyodide tree │
│ ❱ 59 │ │ root = _init_xbuild_env(quiet=quiet) │
│ 60 │ │
│ 61 │ os.environ["PYODIDE_ROOT"] = str(root) │
│ 62 │
│ │
│ /Users/agriyakhetarpal/envs/skimage-dev/lib/python3.13/site-packages/pyodide_build/build_env.py:84 in _init_xbuild_env │
│ │
│ 81 │ with context: │
│ 82 │ │ manager = CrossBuildEnvManager(xbuildenv_path) │
│ 83 │ │ if manager.current_version is None: │
│ ❱ 84 │ │ │ manager.install() │
│ 85 │ │ │
│ 86 │ │ manager.check_version_marker() │
│ 87 │
│ │
│ /Users/agriyakhetarpal/envs/skimage-dev/lib/python3.13/site-packages/pyodide_build/xbuildenv.py:175 in install │
│ │
│ 172 │ │ │ version = _url_to_version(url) │
│ 173 │ │ │ download_url = url │
│ 174 │ │ else: │
│ ❱ 175 │ │ │ version = version or self._find_latest_version() │
│ 176 │ │ │ │
│ 177 │ │ │ local_versions = build_env.local_versions() │
│ 178 │ │ │ release = self._find_remote_release(version) │
│ │
│ /Users/agriyakhetarpal/envs/skimage-dev/lib/python3.13/site-packages/pyodide_build/xbuildenv.py:239 in _find_latest_version │
│ │
│ 236 │ │ ) │
│ 237 │ │ │
│ 238 │ │ if not latest: │
│ ❱ 239 │ │ │ raise ValueError("No compatible cross-build environment found") │
│ 240 │ │ │
│ 241 │ │ return latest.version │
│ 242 │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
ValueError: No compatible cross-build environment found
and running pyodide xbuildenv install 0.27.2 gives
╭───────────────────────────────────────────────────────── Traceback (most recent call last) ──────────────────────────────────────────────────────────╮
│ /Users/agriyakhetarpal/envs/skimage-dev/lib/python3.13/site-packages/pyodide_build/cli/xbuildenv.py:61 in _install │
│ │
│ 58 │ if url: │
│ 59 │ │ manager.install(url=url, force_install=force_install) │
│ 60 │ else: │
│ ❱ 61 │ │ manager.install(version=version, force_install=force_install) │
│ 62 │ │
│ 63 │ typer.echo(f"Pyodide cross-build environment installed at {path.resolve()}") │
│ 64 │
│ │
│ /Users/agriyakhetarpal/envs/skimage-dev/lib/python3.13/site-packages/pyodide_build/xbuildenv.py:183 in install │
│ │
│ 180 │ │ │ │ python_version=local_versions["python"], │
│ 181 │ │ │ │ pyodide_build_version=local_versions["pyodide-build"], │
│ 182 │ │ │ ): │
│ ❱ 183 │ │ │ │ raise ValueError( │
│ 184 │ │ │ │ │ f"Version {version} is not compatible with the current environment." │
│ 185 │ │ │ │ ) │
│ 186 │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
ValueError: Version 0.27.2 is not compatible with the current environment.
So, I checked the Python version and I got Python 3.13.1 (main, Dec 3 2024, 17:59:52) [Clang 16.0.0 (clang-1600.0.26.4)].
I feel that this could be reported better, somehow, perhaps through a simple check when running pyodide build, which sees if sys.version_info >= (3,12) and sys.version_info < (3, 13) returns True (or whichever the value of requires-python is in the metadata) and asks users to switch a supported Python version.