uv: Deduplicate all files in the wheel cache
- ID
- 20000
- Status
- summarized
- Published
- 31 Aug 2026, 2:03 PM
- Fetched
- 02 Sep 2026, 7:24 AM
- Provider
- Hacker News
- Category
- dev-community
- Original URL
- https://github.com/astral-sh/uv/pull/21327
- Source URL
- https://hnrss.org/best
Summary
- Score
- 6.0
- Created
- 02 Sep 2026, 7:27 AM
- Tags
- Audience
- developersvibe_coders
What happened
uv PR #21327 adds file-level deduplication to the wheel cache by storing every file under its BLAKE3 hash in a files-v0 bucket and hardlinking into archive-v0. On the author's machine this saves ~545 MiB (~10% of cache) at the cost of a <4% slowdown on cold installs and no impact on warm installs.
Why it matters
If you run uv in CI or on disk-constrained dev machines, expect roughly 10% smaller caches after this lands; weigh that against a small cold-install penalty if your workflow frequently wipes caches. No action needed for existing installs since hardlinking keeps the installation step unchanged.
Discussion angle
Is a <4% cold-install slowdown worth ~10% cache savings for your CI and local setups, and does file-level dedup change how you'd size ephemeral runner disks?