What’s New

ruff 0.15.21

0.15.21
Added
  • Add `--add-ignore` for adding `ruff:ignore` comments
  • Lint and fix use of deprecated `abc` decorators (`UP051`)
Changed
  • Drop `C409` tuple comprehension preview behavior
  • Avoid whitespace normalization when formatting comments
  • Mark `EXE004` fix as unsafe
  • Mark `PYI061` fixes as unsafe in Python files
  • Skip `overload-with-docstring` in stub files (`D418`)
  • Add `--extend-exclude` to `ruff format`
Fixed
  • Refine non-empty f-string detection
  • Detect syntax errors in individual notebook cells
  • Fix `ISC003` autofix incorrectly stripping `+` from comments
Release Notes

Released on 2026-07-09.

Preview features
  • Add --add-ignore for adding ruff:ignore comments (#26346)
  • [flake8-comprehensions] Drop C409 tuple comprehension preview behavior (#25707)
  • Avoid whitespace normalization when formatting comments (#26455)
  • [pyupgrade] Lint and fix use of deprecated abc decorators (UP051) (#26417)
Bug fixes
  • Refine non-empty f-string detection (#26526)
  • Detect syntax errors in individual notebook cells (#26419)
  • [flake8-implicit-str-concat] Fix ISC003 autofix incorrectly stripping + from comments (#26554)
Rule changes
  • [flake8-executable] Mark EXE004 fix as unsafe (#26033)
  • [flake8-pyi] Mark PYI061 fixes as unsafe in Python files (#26533)
  • [pydocstyle] Skip overload-with-docstring in stub files (D418) (#26318)
Performance
  • Avoid per-token source index visitor calls (#26506)
  • Cache parenthesized expression boundaries in the formatter (#26344)
  • Improve performance of rendering edits in preview mode (#26565)
  • Inline fits_element in formatter (#26429)
  • Inline formatter printing hot paths (#26504)
  • Lazily create builtin bindings (#26510)
  • Skip empty trivia scans in the source indexer (#26507)
  • Use ICF for macOS release builds (#25780)
Formatter
  • Add --extend-exclude to ruff format (#26372)
Documentation
  • Add "How does Ruff's import sorting compare to isort?" link to README (#26530)
  • Fix Mozilla Firefox repository link in README (#26537)
  • [flake8-bandit] Fix misleading docstring for mako-templates (S702) (#26432)
  • [ruff] Fix non-triggering example for if-key-in-dict-del (RUF051) (#26433)
Contributors
Install ruff 0.15.21
Install prebuilt binaries via shell script
curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ruff/releases/download/0.15.21/ruff-installer.sh | sh
Install prebuilt binaries via powershell script
powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ruff/releases/download/0.15.21/ruff-installer.ps1 | iex"
Download ruff 0.15.21
FilePlatformChecksum
ruff-aarch64-apple-darwin.tar.gzApple Silicon macOSchecksum
ruff-x86_64-apple-darwin.tar.gzIntel macOSchecksum
ruff-aarch64-pc-windows-msvc.zipARM64 Windowschecksum
ruff-i686-pc-windows-msvc.zipx86 Windowschecksum
ruff-x86_64-pc-windows-msvc.zipx64 Windowschecksum
ruff-aarch64-unknown-linux-gnu.tar.gzARM64 Linuxchecksum
ruff-i686-unknown-linux-gnu.tar.gzx86 Linuxchecksum
ruff-powerpc64-unknown-linux-gnu.tar.gzPPC64 Linuxchecksum
ruff-powerpc64le-unknown-linux-gnu.tar.gzPPC64LE Linuxchecksum
ruff-riscv64gc-unknown-linux-gnu.tar.gzRISCV Linuxchecksum
ruff-s390x-unknown-linux-gnu.tar.gzS390x Linuxchecksum
ruff-x86_64-unknown-linux-gnu.tar.gzx64 Linuxchecksum
ruff-armv7-unknown-linux-gnueabihf.tar.gzARMv7 Linuxchecksum
ruff-aarch64-unknown-linux-musl.tar.gzARM64 MUSL Linuxchecksum
ruff-i686-unknown-linux-musl.tar.gzx86 MUSL Linuxchecksum
ruff-x86_64-unknown-linux-musl.tar.gzx64 MUSL Linuxchecksum
ruff-arm-unknown-linux-musleabihf.tar.gzARMv6 MUSL Linux (Hardfloat)checksum
ruff-armv7-unknown-linux-musleabihf.tar.gzARMv7 MUSL Linuxchecksum
Verifying GitHub Artifact Attestations

The artifacts in this release have attestations generated with GitHub Artifact Attestations. These can be verified by using the GitHub CLI:

gh attestation verify <file-path of downloaded artifact> --repo astral-sh/ruff

You can also download the attestation from GitHub and verify against that directly:

gh attestation verify <file-path of downloaded artifact> --bundle <file-path of downloaded attestation>
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