# uv 0.12.6

- Product: uv (https://whatsnew.fyi/product/uv)
- Vendor: uv
- Date: 2026-08-25
- Version: 0.12.6
- Original notes: https://github.com/astral-sh/uv/releases/tag/0.12.6
- Permalink: https://whatsnew.fyi/product/uv/releases/0.12.6

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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- **changed** — Update CPython to use OpenSSL 3.5.8 and libffi 3.4.8
- **changed** — Report cache-cleaning space savings from filesystem block allocation and avoid double-counting hard links
- **changed** — Limit warnings about unbounded uv_build requirements to source-distribution builds
- **changed** — Display byte counts below 1 KiB without a fractional part
- **added** — Add uv workspace metadata --sync --exact to remove packages outside the selected resolution
- **added** — Add the artifact-hash-filtering preview feature to make uv pip compile --generate-hashes honor --only-binary and --no-binary
- **changed** — Respect package-specific exclude-newer cutoffs when uv check selects its ty executable
- **changed** — Preserve virtual-environment hints from tar-codec source-distribution errors when the base interpreter is outside a bin directory
- **changed** — Enable profile-guided optimization for Linux x86-64 release binaries
- **changed** — Enable profile-guided optimization for Windows x86-64 release binaries
- **changed** — Enable profile-guided optimization for macOS ARM64 release binaries
- **changed** — Enable profile-guided optimization for Linux ARM64 release binaries
- **changed** — Speed up syncing projects with many activated conflict items by reusing their encoded representation
- **fixed** — Allow explicit uv build and non-editable first-party workspace packages when no-build is enabled
- **fixed** — Reuse configured index credentials during uv tool upgrade when the tool receipt references the same index
- **fixed** — Ensure full 40-character Git commit pins resolve to the requested object instead of a SHA-named branch
- **fixed** — Prevent TLS segfaults in riscv64 musl release binaries
- **fixed** — Preserve dependencies selected by recursive extras when markers mix production and extra conditions
- **fixed** — Preserve version constraints from transitively referenced recursive extras
- **fixed** — Resolve repository-relative Git archive dependencies inside the checkout during the initial uv sync

##### Release Notes

Released on 2026-08-25.

###### Python

- Update CPython to use OpenSSL 3.5.8 and libffi 3.4.8 [#21295](https://github.com/astral-sh/uv/pull/21295))
###### Enhancements

- Report cache-cleaning space savings from filesystem block allocation and avoid double-counting hard links ([#21261](https://github.com/astral-sh/uv/pull/21261))
- Limit warnings about unbounded `uv_build` requirements to source-distribution builds ([#21078](https://github.com/astral-sh/uv/pull/21078))
- Display byte counts below 1 KiB without a fractional part ([#21237](https://github.com/astral-sh/uv/pull/21237))

###### Preview features

- Add `uv workspace metadata --sync --exact` to remove packages outside the selected resolution ([#21117](https://github.com/astral-sh/uv/pull/21117))
- Add the `artifact-hash-filtering` preview feature to make `uv pip compile --generate-hashes` honor `--only-binary` and `--no-binary` ([#21235](https://github.com/astral-sh/uv/pull/21235))
- Respect package-specific `exclude-newer` cutoffs when `uv check` selects its `ty` executable ([#21227](https://github.com/astral-sh/uv/pull/21227))
- Preserve virtual-environment hints from `tar-codec` source-distribution errors when the base interpreter is outside a `bin` directory ([#21146](https://github.com/astral-sh/uv/pull/21146))

###### Performance

- Enable profile-guided optimization for Linux x86-64 release binaries ([#21001](https://github.com/astral-sh/uv/pull/21001))
- Enable profile-guided optimization for Windows x86-64 release binaries ([#21003](https://github.com/astral-sh/uv/pull/21003))
- Enable profile-guided optimization for macOS ARM64 release binaries ([#21002](https://github.com/astral-sh/uv/pull/21002))
- Enable profile-guided optimization for Linux ARM64 release binaries ([#21004](https://github.com/astral-sh/uv/pull/21004))
- Speed up syncing projects with many activated conflict items by reusing their encoded representation ([#21148](https://github.com/astral-sh/uv/pull/21148))

###### Bug fixes

- Allow explicit `uv build` and non-editable first-party workspace packages when `no-build` is enabled ([#21294](https://github.com/astral-sh/uv/pull/21294))
- Reuse configured index credentials during `uv tool upgrade` when the tool receipt references the same index ([#21275](https://github.com/astral-sh/uv/pull/21275))
- Ensure full 40-character Git commit pins resolve to the requested object instead of a SHA-named branch ([#21224](https://github.com/astral-sh/uv/pull/21224))
- Prevent TLS segfaults in riscv64 musl release binaries ([#21158](https://github.com/astral-sh/uv/pull/21158))
- Preserve dependencies selected by recursive extras when markers mix production and extra conditions ([#21181](https://github.com/astral-sh/uv/pull/21181))
- Preserve version constraints from transitively referenced recursive extras ([#21209](https://github.com/astral-sh/uv/pull/21209))
- Resolve repository-relative Git archive dependencies inside the checkout during the initial `uv sync` ([#21264](https://github.com/astral-sh/uv/pull/21264))
- Return an error instead of panicking when a bearer token cannot be encoded as an HTTP header ([#21282](https://github.com/astral-sh/uv/pull/21282))
- Do not misclassify package URLs ending in `.py` as local script paths ([#21144](https://github.com/astral-sh/uv/pull/21144))
- Use directory creation times consistently across libc implementations for directory `cache-keys` entries ([#21137](https://github.com/astral-sh/uv/pull/21137))
- Promote human-readable sizes to the next unit at rounding boundaries ([#21136](https://github.com/astral-sh/uv/pull/21136))

###### Other changes

- Add Python 3.15 release-candidate Docker images ([#21293](https://github.com/astral-sh/uv/pull/21293))
- Raise the minimum supported Rust version to 1.96 and update the repository toolchain to Rust 1.98 ([#21258](https://github.com/astral-sh/uv/pull/21258))

##### Install uv 0.12.6

###### Install prebuilt binaries via shell script

```sh
curl

_[Truncated at 4000 characters — full notes: https://github.com/astral-sh/uv/releases/tag/0.12.6]_