Pixi environment: 30s Jupyter kernel startup delay due to `Failed to get activated env vars` timeout

[hadim]

Bug Report

Environment

• OS: macOS arm64 (Apple Silicon)
• VS Code: latest stable
• ms-python.python: 2026.2.0
• ms-python.vscode-python-envs: 1.17.x
• ms-toolsai.jupyter: 2025.10.x
• Pixi: 0.63.1
• Python: 3.12.12 (managed by Pixi)
• ipykernel: 7.2.0

Description

Since updating ms-python.python to 2026.2.0 (with ms-python.vscode-python-envs also installed), every Jupyter kernel startup is delayed by exactly 30 seconds. The extension attempts to collect activated environment variables for the Pixi environment but times out because Pixi environments are not recognized (detected as Unknown).

The kernel does eventually start and works correctly, but the 30-second delay on every kernel start/restart makes the development experience very frustrating.

This was not an issue with previous versions of ms-python.python (2026.1.x and earlier).

Logs

15:53:54.422 [info] Starting Kernel (Python Path: ~/.pixi/envs/default/bin/python, Unknown, 3.12.12) for 'notebooks/Embedding.ipynb' (disableUI=true)
15:54:24.611 [warn] Failed to get activated env vars for ~/.pixi/envs/default/bin/python in 30011ms
15:54:24.613 [warn] Failed to get activated env vars for ~/.pixi/envs/default/bin/python in 30011ms
15:54:24.613 [info] Process Execution: ~/.pixi/envs/default/bin/python -c "import ipykernel; ..."
15:54:24.613 [info] Process Execution: ~/.pixi/envs/default/bin/python -m ipykernel_launcher --f=...
15:54:25.053 [info] Kernel successfully started

Note the exact 30-second gap between Starting Kernel and Kernel successfully started, caused by the Failed to get activated env vars timeout. The environment type is reported as Unknown — Pixi is not recognized as a known environment type.

Running pixi shell in a terminal is near-instant, so the issue is not with Pixi itself but with how the extension attempts to activate the environment.

Steps to Reproduce

1. Have a Pixi project with ipykernel as a dependency
2. Have ms-python.python 2026.2.0 and ms-python.vscode-python-envs installed
3. Open a Jupyter notebook in VS Code
4. Select the Pixi environment interpreter (.pixi/envs/default/bin/python)
5. Start or restart the kernel
6. Observe the 30-second delay before the kernel is ready

Workaround

Downgrading ms-python.python to a version prior to 2026.2.0 and uninstalling ms-python.vscode-python-envs immediately resolves the issue — kernel startup becomes instant again.

Expected Behavior

Pixi environments should either be recognized and activated properly, or the activation attempt should fail fast instead of blocking for 30 seconds.

Related Issues

• Python environment terminal activation breaks debugger launch #25192 — Similar pixi shell activation issue affecting the debugger (same root cause: getActivatedEnvironmentVariables timeout)
• prefix-dev/pixi#5099 — Same Failed to get activated env vars log with Pixi + VS Code

[hadim]

After more investigation, I've isolated the root cause: this issue is not caused by the Python extension but by ms-python.vscode-python-envs.

Findings:

• With ms-python.vscode-python-envs installed: 30s kernel startup delay every time a notebook is opened
• With ms-python.vscode-python-envs uninstalled: kernel starts instantly
• Python extension version (2026.2) has no effect either way

The relevant log line is:

[warn] Failed to get activated env vars for .../.pixi/envs/default/bin/python in 30017ms

This timeout is triggered by the envs extension attempting to collect activated environment variables for the pixi-managed environment and failing after exactly 30 seconds.

I've opened a dedicated issue on the correct repo: microsoft/vscode-python-environments#1253

Closing this one as misfiled. Workaround: uninstall ms-python.vscode-python-envs.