Exception in multi-root workspace without "path".

python/vscode_common_python_lsp/server.py の、指定されたソース行にある update_workspace_settings の周辺から始め、示されているマルチルートワークスペース構成で障害を再現します。ファイルシステムパスのないワークスペースエントリがどのように処理されるかを追跡します。完了条件は、リモートワークスペースで初期化時に NoneType パス例外が発生しなくなり、影響を受ける言語サーバーが正常に起動することです。

When using the MicroPico extension, for example, with its Remote Workspace support that adds a multi-root workspace as such:

{
	"folders": [
		{
			"path": "."
		},
		{
			"name": "Mpy Remote Workspace",
			"uri": "pico:"
		}
	]
}

The Pylint server (ms-python.pylint) appears to fail because of a non-existent "path" attribute (or similar). I'm also seeing the same error with both the Black Formatter (ms-python.black-formatter) and isort (ms-python.isort), ending with the same stack frames.

[info] Server: Start requested.
[info] Exception occurred for message "0"
Traceback (most recent call last):
  File "***\.vscode\extensions\ms-python.pylint-2026.7.11691008\bundled\libs\pygls\protocol\json_rpc.py", line 300, in _send_handler_result
    self._send_response(msg_id, result=future.result())
                                       ~~~~~~~~~~~~~^^
  File "C:\Program Files\Python314\Lib\concurrent\futures\_base.py", line 447, in result
    return self.__get_result()
           ~~~~~~~~~~~~~~~~~^^
  File "C:\Program Files\Python314\Lib\concurrent\futures\_base.py", line 396, in __get_result
    raise self._exception
  File "***\.vscode\extensions\ms-python.pylint-2026.7.11691008\bundled\libs\pygls\protocol\json_rpc.py", line 273, in _run_generator
    value = future.result() if future is not None else None
            ~~~~~~~~~~~~~^^
  File "C:\Program Files\Python314\Lib\concurrent\futures\_base.py", line 447, in result
    return self.__get_result()
           ~~~~~~~~~~~~~~~~~^^
  File "C:\Program Files\Python314\Lib\concurrent\futures\_base.py", line 396, in __get_result
    raise self._exception
  File "***\.vscode\extensions\ms-python.pylint-2026.7.11691008\bundled\libs\pygls\protocol\json_rpc.py", line 236, in _execute_handler
    result = handler(*args, **kwargs)
  File "***\.vscode\extensions\ms-python.pylint-2026.7.11691008\bundled\tool\lsp_server.py", line 718, in initialize
    tool_server.apply_settings(params)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
  File "***\.vscode\extensions\ms-python.pylint-2026.7.11691008\bundled\libs\vscode_common_python_lsp\server.py", line 482, in apply_settings
    self.update_workspace_settings(settings)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "***\.vscode\extensions\ms-python.pylint-2026.7.11691008\bundled\libs\vscode_common_python_lsp\server.py", line 152, in update_workspace_settings
    key = normalize_path(
        uris.to_fs_path(setting["workspace"]),
        resolve_symlinks=self.config.resolve_symlinks,
    )
  File "***\.vscode\extensions\ms-python.pylint-2026.7.11691008\bundled\libs\vscode_common_python_lsp\paths.py", line 236, in normalize_path
    path = pathlib.Path(file_path)
  File "C:\Program Files\Python314\Lib\pathlib\__init__.py", line 150, in __init__
    raise TypeError(
    ...<2 lines>...
        f"not {type(path).__name__!r}")
TypeError: argument should be a str or an os.PathLike object where __fspath__ returns a str, not 'NoneType'

[info] [Error] Server initialization failed.

Relevant source: https://github.com/microsoft/vscode-common-python-lsp/blob/0258b220929850986b1d9413ac27b203a72acc04/python/vscode_common_python_lsp/server.py#L137

Workarounds

A workaround is to disable the Remote Workspace, and not enable until after the analysis servers have already started.