Description

Starting the SQLMesh Language Server (via tcloud / enterprise LSP) fails during import: sqlmesh.lsp.main imports WorkspaceDiagnosticRefreshRequest from lsprotocol.types, but that symbol is not available in lsprotocol 2025.x, so the process exits and the VS Code extension reports a failed LSP connection.

Environment

• OS: Windows
• Editor: VS Code / Cursor + SQLMesh extension
• Python: 3.11 (project .venv as workspace interpreter)

Steps to reproduce

1. Install current tcloud in a clean venv (e.g. pip install tcloud).
2. Open a SQLMesh project and use that venv as the Python interpreter.
3. Trigger the SQLMesh extension / LSP (e.g. reload window).

Expected

Language server starts without import errors.

Actual

Server process exits with:
ImportError: cannot import name 'WorkspaceDiagnosticRefreshRequest' from 'lsprotocol.types'

(Extension may also show generic LSP errors such as “couldn’t create connection to server” or exit code 1.)

Versions

Workaround

pip uninstall -y lsprotocol pygls
pip install "lsprotocol<2025" "pygls<2.0"
python -c "from lsprotocol.types import WorkspaceDiagnosticRefreshRequest; print('ok')"