Uv

Enhancements

- Add dependents ("via ..." comments) in `uv export` command ([12350](https://github.com/astral-sh/uv/pull/12350))
- Bump least-recent non-EOL macOS version to 13.0 ([12518](https://github.com/astral-sh/uv/pull/12518))
- Support `--find-links`-style "flat" indexes in `[[tool.uv.index]]` ([12407](https://github.com/astral-sh/uv/pull/12407))
- Distinguish between `-q` and `-qq` ([12300](https://github.com/astral-sh/uv/pull/12300))

Configuration

- Support `UV_PROJECT` environment to set project directory. ([12327](https://github.com/astral-sh/uv/pull/12327))

Performance

- Use a boxed slice for various requirement types ([12514](https://github.com/astral-sh/uv/pull/12514))

Bug fixes

- Add a newline after metadata when initializing scripts with other metadata blocks ([12501](https://github.com/astral-sh/uv/pull/12501))
- Avoid writing empty `requires-python` to script blocks ([12517](https://github.com/astral-sh/uv/pull/12517))
- Respect build constraints in `uv sync` ([12502](https://github.com/astral-sh/uv/pull/12502))
- Respect transitive dependencies in `uv tree --only-group` ([12560](https://github.com/astral-sh/uv/pull/12560))

Enhancements

- Add `uv sync --check` flag ([12342](https://github.com/astral-sh/uv/pull/12342))
- Add support for Python version requests in `uv python list` ([12375](https://github.com/astral-sh/uv/pull/12375))
- Support `.env` files in `uv tool run` ([12386](https://github.com/astral-sh/uv/pull/12386))
- Support `python find --script` ([11891](https://github.com/astral-sh/uv/pull/11891))

Preview features

- Check all compatible torch indexes when `--torch-backend` is enabled ([12385](https://github.com/astral-sh/uv/pull/12385))

Performance

- Use a boxed slice for extras and groups ([12391](https://github.com/astral-sh/uv/pull/12391))
- Use small string for index name type ([12355](https://github.com/astral-sh/uv/pull/12355))

Bug fixes

- Allow virtual packages with `--no-build` ([12314](https://github.com/astral-sh/uv/pull/12314))
- Ignore `--find-links` entries for pinned indexes ([12396](https://github.com/astral-sh/uv/pull/12396))
- Omit wheels from lockfile based on `--exclude-newer` ([12299](https://github.com/astral-sh/uv/pull/12299))
- Retain end-of-line comment position when adding dependency ([12360](https://github.com/astral-sh/uv/pull/12360))
- Omit fragment when querying for wheels in Simple HTML API ([12384](https://github.com/astral-sh/uv/pull/12384))
- Error on missing argument in `requirements.txt` ([12354](https://github.com/astral-sh/uv/pull/12354))
- Support modules with different casing in build backend ([12240](https://github.com/astral-sh/uv/pull/12240))
- Add authentication policy support for `pip` commands ([12470](https://github.com/astral-sh/uv/pull/12470))

Enhancements

- Use `keyring --mode creds` when `authenticate = "always"` ([12316](https://github.com/astral-sh/uv/pull/12316))
- Fail with specific error message when no password is present and `authenticate = "always"` ([12313](https://github.com/astral-sh/uv/pull/12313))

Bug fixes

- Add boolish value parser for `UV_MANAGED_PYTHON` flags ([12345](https://github.com/astral-sh/uv/pull/12345))
- Make deserialization non-fatal when assessing source tree revisions ([12319](https://github.com/astral-sh/uv/pull/12319))
- Use resolver-returned wheel over alternate cached wheel ([12301](https://github.com/astral-sh/uv/pull/12301))

Documentation

- Add experimental `--torch-backend` to the PyTorch guide ([12317](https://github.com/astral-sh/uv/pull/12317))
- Fix `keyring-provider` references in alternative index docs ([12315](https://github.com/astral-sh/uv/pull/12315))
- Fix `--directory` path in examples ([12165](https://github.com/astral-sh/uv/pull/12165))

Preview changes

- Automatically infer the PyTorch index via `--torch-backend=auto` ([12070](https://github.com/astral-sh/uv/pull/12070))

Enhancements

- Add support for enabling all groups by default with `default-groups = "all"` ([12289](https://github.com/astral-sh/uv/pull/12289))
- Add simpler `--managed-python` and `--no-managed-python` flags for toggling Python preferences ([12246](https://github.com/astral-sh/uv/pull/12246))

Performance

- Avoid allocations for default cache keys ([12063](https://github.com/astral-sh/uv/pull/12063))

Bug fixes

- Allow local version mismatches when validating lockfile ([12285](https://github.com/astral-sh/uv/pull/12285))
- Allow owned string when deserializing `requires-python` ([12278](https://github.com/astral-sh/uv/pull/12278))
- Make cache errors non-fatal in `Planner::build` ([12281](https://github.com/astral-sh/uv/pull/12281))

Python

- Add CPython 3.14.0a6
- Fix regression where extension modules would use wrong `CXX` compiler on Linux
- Enable FTS3 enhanced query syntax for SQLite

See the [`python-build-standalone` release notes](https://github.com/astral-sh/python-build-standalone/releases/tag/20250317) for more details.

Enhancements

- Add support for `-c` constraints in `uv add` ([12209](https://github.com/astral-sh/uv/pull/12209))
- Add support for `--global` default version in `uv python pin` ([12115](https://github.com/astral-sh/uv/pull/12115))
- Always reinstall local source trees passed to `uv pip install` ([12176](https://github.com/astral-sh/uv/pull/12176))
- Render token claims on publish permission error ([12135](https://github.com/astral-sh/uv/pull/12135))
- Add pip-compatible `--group` flag to `uv pip install` and `uv pip compile` ([11686](https://github.com/astral-sh/uv/pull/11686))

Preview features

- Avoid creating duplicate directory entries in built wheels ([12206](https://github.com/astral-sh/uv/pull/12206))
- Allow overriding module names for editable builds ([12137](https://github.com/astral-sh/uv/pull/12137))

Performance

- Avoid replicating core-metadata field on `File` struct ([12159](https://github.com/astral-sh/uv/pull/12159))

Bug fixes

- Add `src` to default cache keys ([12062](https://github.com/astral-sh/uv/pull/12062))
- Discard insufficient fork markers ([10682](https://github.com/astral-sh/uv/pull/10682))
- Ensure `python pin --global` creates parent directories if missing ([12180](https://github.com/astral-sh/uv/pull/12180))
- Fix GraalPy abi tag parsing and discovery ([12154](https://github.com/astral-sh/uv/pull/12154))
- Remove extraneous script packages in `uv sync --script` ([12158](https://github.com/astral-sh/uv/pull/12158))
- Remove redundant `activate.bat` output ([12160](https://github.com/astral-sh/uv/pull/12160))
- Avoid subsequent index hint when no versions are available on the first index ([9332](https://github.com/astral-sh/uv/pull/9332))
- Error on lockfiles with incoherent wheel versions ([12235](https://github.com/astral-sh/uv/pull/12235))

Rust API

- Update `BaseClientBuild` to accept custom proxies ([12232](https://github.com/astral-sh/uv/pull/12232))

Documentation

- Make testpypi index explicit in example snippet ([12148](https://github.com/astral-sh/uv/pull/12148))
- Reverse and format the archived changelogs ([12099](https://github.com/astral-sh/uv/pull/12099))
- Use consistent commas around i.e. and e.g. ([12157](https://github.com/astral-sh/uv/pull/12157))
- Fix typos in MRE docs ([12198](https://github.com/astral-sh/uv/pull/12198))
- Fix double space typo ([12171](https://github.com/astral-sh/uv/pull/12171))

Python

- Add support for dynamic musl Python distributions on x86-64 Linux ([12121](https://github.com/astral-sh/uv/pull/12121))
- Allow the experimental JIT to be enabled at runtime on Python 3.13 and 3.14 on Linux
- Upgrade the build toolchain to LLVM 20, improving performance

See the [`python-build-standalone` release notes](https://github.com/astral-sh/python-build-standalone/releases/tag/20250311) for more details.

Enhancements

- Add `--marker` flag to `uv add` ([12012](https://github.com/astral-sh/uv/pull/12012))
- Allow overriding module name for uv build backend ([11884](https://github.com/astral-sh/uv/pull/11884))
- Sync latest Python releases ([12120](https://github.com/astral-sh/uv/pull/12120))
- Use 'Upload' instead of 'Download' in publish reporter ([12029](https://github.com/astral-sh/uv/pull/12029))
- Add `[index].authenticate` allowing authentication to be required on an index ([11896](https://github.com/astral-sh/uv/pull/11896))
- Add support for Windows legacy scripts in `uv tool run` ([12079](https://github.com/astral-sh/uv/pull/12079))
- Propagate conflicting dependency groups when using `include-group` ([12005](https://github.com/astral-sh/uv/pull/12005))
- Show ambiguous requirements when `uv add` failed ([12106](https://github.com/astral-sh/uv/pull/12106))

Performance

- Cache workspace discovery ([12096](https://github.com/astral-sh/uv/pull/12096))
- Insert dependencies into fork state prior to fetching metadata ([12057](https://github.com/astral-sh/uv/pull/12057))
- Remove some allocations from `uv-auth` ([12077](https://github.com/astral-sh/uv/pull/12077))

Bug fixes

- Avoid considering `PATH` updated when the `export` is commented in the shellrc ([12043](https://github.com/astral-sh/uv/pull/12043))
- Fix `uv publish` retry on network failures ([12041](https://github.com/astral-sh/uv/pull/12041))
- Use a sized stream in `uv publish` to comply with WSGI PyPI server constraints ([12111](https://github.com/astral-sh/uv/pull/12111))
- Fix `uv python install --reinstall` when the version was not previously installed ([12124](https://github.com/astral-sh/uv/pull/12124))

Preview features

- Fix `uv_build` invocation ([12058](https://github.com/astral-sh/uv/pull/12058))

Documentation

- Quote versions string in `python-versions.md` ([12112](https://github.com/astral-sh/uv/pull/12112))
- Fix tool concept page headings ([12053](https://github.com/astral-sh/uv/pull/12053))
- Update the `[index].authenticate` docs ([12102](https://github.com/astral-sh/uv/pull/12102))
- Update versioning policy ([11666](https://github.com/astral-sh/uv/pull/11666))