astral-sh/ty 0.0.42

on GitHub

Release Notes

Released on 2026-06-01.

Bug fixes

• Fix narrowing of enum literal unions by member identity (#25520)
• Detect recursive expansion in constraint-set solving (#25442)

Core type checking

• Support tagged-union narrowing for nominal types (#24916)
• Extend Generator assignability workaround to Python 3.13+ (#25472)
• Sync vendored typeshed stubs (#25514)

Performance

• Avoid redundant work for empty collection context (#25527)
• Deduplicate retained use-def place states (#25450)
• Compact retained semantic maps (#25238)

Contributors

• @aholyoke
• @carljm
• @charliermarsh
• @sharkdp

Install ty 0.0.42

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.42/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.42/ty-installer.ps1 | iex"

Download ty 0.0.42

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>