astral-sh/ty 0.0.49

on GitHub

Release Notes

Released on 2026-06-11.

Bug fixes

• Fix site-package error when multiple versions of Python are installed in system path (#25769)

Diagnostics

• Point at attribute's binding site in `invalid-await diagnostic (#24628)
• Report redefined legacy TypeVars (#25854)

Performance

• Add dedicated TDDs for narrowing constraints (#25834)
• Avoid caching same-file raw signatures (#25761)
• Cache reachability evaluations during inference (#25696)
• Compact retained definition maps (#25737)
• Omit redundant definition inference owner keys (#25837)

Core type checking

• Preserve nominal type of enum.property instances (#25849)
• Restrict length narrowing to types that encode their length (#25840)
• Use peer context for collection literals (#25848)

Contributors

• @charliermarsh
• @anishgirianish
• @cheparity
• @carljm

Install ty 0.0.49

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.49/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.49/ty-installer.ps1 | iex"

Download ty 0.0.49

Verifying GitHub Artifact Attestations

The artifacts in this release have attestations generated with GitHub Artifact Attestations. These can be verified by using the GitHub CLI:

gh attestation verify <file-path of downloaded artifact> --repo astral-sh/ty

You can also download the attestation from GitHub and verify against that directly:

gh attestation verify <file-path of downloaded artifact> --bundle <file-path of downloaded attestation>