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Public story · 2026-08-31 · high
Astral's Charlie Marsh reclaimed 545 MiB on one machine by hashing cache files with BLAKE3 instead of whole wheels.
Why now: The dedup pull request is still open with no merge date set, as of August 31.
uv's PR #21327 rewrites the package manager's wheel cache to dedupe individual files instead of whole wheels, hashing each payload with BLAKE3.
The point is disk space. Astral's Charlie Marsh reclaimed about 545.2 MiB on one test machine. That's roughly 10% of that machine's cache, which matters most for anyone running many virtual environments or rebuilding containers often.
Payload files get hashed once and stored in a shared files-v0 bucket. They're then hardlinked back into the original archive layout, so installs behave the same as before. Nothing about how uv resolves or installs packages changes.
It costs something. Cold installs run 3-4% slower with the change, while warm installs show no difference. Marsh paired the dedup PR with a separate buffer-reuse change, PR #21340, and says the pair beats uv's current install speed too.
None of this is in a release yet. The PR sits behind a preview flag, with no version number attached.
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Shared entity: MiB / Same source domain / Earlier coverage / Tension
Both cover MiB; reported by the same outlet (github.com); earlier MiB coverage from 2026-08-09.
Shared entity: MiB / Same source domain / Earlier coverage
Both cover MiB; reported by the same outlet (github.com); earlier MiB coverage from 2026-08-25.
Both cover MiB; reported by the same outlet (github.com); earlier MiB coverage from 2026-08-25.
Both cover MiB; reported by the same outlet (github.com); earlier MiB coverage from 2026-08-24.
Both cover MiB; reported by the same outlet (github.com); earlier MiB coverage from 2026-08-14.
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Both cover Paired; reported by the same outlet (github.com); earlier Paired coverage from 2026-08-11.
Both cover Paired; reported by the same outlet (github.com); earlier Paired coverage from 2026-08-11.
Shared entity: MiB / Same source domain / Earlier coverage
Both cover MiB; reported by the same outlet (github.com); earlier MiB coverage from 2026-08-09.