# Crystal 1.20.2

- Product: Crystal (https://whatsnew.fyi/product/crystal)
- Vendor: Crystal Language
- Date: 2026-05-15
- Version: 1.20.2
- Original notes: https://github.com/crystal-lang/crystal/releases/tag/1.20.2
- Permalink: https://whatsnew.fyi/product/crystal/releases/1.20.2

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **fixed** — Simplify Sync::Mutex#synchronize proc type constraints
- **fixed** — Range#sample eventually loses randomness

###### Bugfixes

###### stdlib

- _(concurrency)_ **[regression]** Simplify `Sync::Mutex#synchronize` proc type constraints ([#16904], [#16937], thanks @ysbaddaden)
- _(runtime)_ `Range#sample` eventually loses randomness ([#16909], thanks @ysbaddaden)

[#16904]: https://github.com/crystal-lang/crystal/pull/16904
[#16909]: https://github.com/crystal-lang/crystal/pull/16909
[#16937]: https://github.com/crystal-lang/crystal/pull/16937

###### Infrastructure

- Changelog for 1.20.2 ([#16945], thanks @straight-shoota)

[#16945]: https://github.com/crystal-lang/crystal/pull/16945