Changes

master (unreleased)

36.0 (2026-02-19)

New Features

  • [#2047]: Add javascript-oxlint checker for JavaScript and TypeScript using oxlint.

  • [#1757]: Add org-lint checker for Org mode files. The checker uses Emacs’ built-in org-lint command to detect issues such as invalid links, dead links, and duplicate IDs.

  • [#2132]: Add the flycheck-shellcheck-infer-shell option to the sh-shellcheck checker.

  • [#1977]: Add flycheck-shellcheck-args for passing extra command-line arguments to ShellCheck.

  • [#1854]: Add flycheck-shellcheck-enabled-checks option to enable optional ShellCheck checks via the --enable flag.

  • [#2139]: Add compatibility with Proselint 0.16.

  • [#1574]: Enable proselint checker for reStructuredText mode and chain it after the rst and rst-sphinx checkers.

  • [#1874]: Add flycheck-error-list-after-jump-hook, run after jumping from the error list to an error location.

  • [#2137]: Allow flycheck-command-map to be used as a prefix command with keymap-set and similar functions.

  • [#1833]: Automatically re-check the buffer after revert-buffer (e.g. when using global-auto-revert-mode).

  • [#1134]: Add error explainer for the python-ruff checker.

  • [#1979]: Show pyright rule names (e.g. reportGeneralTypeIssues) as error IDs.

  • [#2134]: Include info-level errors in the mode-line indicator (format: errors|warnings|infos).

Bugs fixed

  • [#2131]: Mitigate CVE-2024-53920 in the emacs-lisp checker subprocess by disabling local eval directives and restricting local variables to safe values during byte-compilation.

  • [#2144]: Rewrite org-lint checker to run in the current Emacs process instead of a -Q --batch subprocess. This eliminates false “Unknown source block language” warnings for languages from external packages.

  • [#2043]: Fix rust checker temp directory error by using --emit=metadata --out-dir instead of --emit=mir -o /dev/null. Also fixes the checker on Windows where /dev/null does not exist.

  • [#1859]: Force C locale (LC_ALL=C) for checker processes to ensure English output. Fixes error pattern matching in non-English locales.

  • [#1919]: Isolate bidi characters in error message snippets using Unicode directional isolates to prevent formatting corruption.

  • [#1856]: Strictly enforce flycheck-navigation-minimum-level. Previously, setting the minimum level would still navigate to lower-severity errors when no errors at the minimum level existed.

  • [#1918]: Exclude the *Flycheck error messages* buffer from global-flycheck-mode.

  • [#1908]: Increase error list File column width from 6 to 12 characters.

  • [#1882]: Fix Go build tags to use comma-separated format instead of repeated -tags flags.

  • [#2098]: Fix tex-chktex error parsing with --inputfiles.

  • [#2143]: Fix compilation warnings on Emacs 30 (obsolete rx-constituents and missing defcustom type spec).

  • [#2089]: Make flycheck-protoc-import-path buffer-local so different protobuf projects can have different import paths.

  • [#2032]: Guard Tools menu operations for Emacs configurations that remove the Tools menu (e.g. Doom Emacs).

  • [#1805]: Preserve match data in idle trigger timer handler.

  • [#1170]: Skip error list highlighting when the error list buffer is not visible, improving performance on every post-command-hook.

  • [#1153]: Handle puppet-parser errors without line numbers (e.g. “Syntax error at end of file”).

  • [#1886]: Fix continuation indicator appearing on non-wrapped lines by using wrap-prefix instead of line-prefix.

  • [#2062]: Fall back to python executable when python3 is unavailable (e.g. Windows with Anaconda/Miniforge).

  • [#2127]: Preserve pre-existing line-prefix text properties (e.g. from org-indent-mode) when adding flycheck overlays.

  • [#2086]: Fix the name of the PyMarkdown config.

  • [#2036]: Fix awk-gawk checker passing spurious quotes to gawk --source.

  • [#2092]: Detect parse errors (unbalanced parentheses, invalid read syntax) in emacs-lisp byte compilation.

  • [#2090]: Fix python-ruff checker to use concise output format instead of removed text format (renamed in ruff 0.2).

  • Fix python-ruff error ID regex and invalid-syntax error handling.

  • Fix rpm-rpmlint error filter returning unfiltered errors (the (none) filename filter was not applied).

  • Add php-ts-mode to the php-phpcs-changed checker.

  • [#1926]: Fix flycheck-cuda-gencodes customize type (was file, now string).

  • Guard buffer-file-name against nil in yaml-actionlint predicate, erlang enabled check, and flycheck-rebar3-project-root.

  • Fix python-pycompile to verify python3 actually works instead of just checking it exists.

  • Fix proselint version detection breaking checker validation.

Removed

  • Remove typescript-tslint checker. TSLint has been deprecated since 2019 in favor of ESLint with typescript-eslint.

  • Remove sass and scss checkers. Ruby Sass reached end-of-life in March 2019. Use sass-stylelint and scss-stylelint instead.

  • Remove sass/scss-sass-lint checker. sass-lint has been abandoned for over 4 years. Use sass-stylelint or scss-stylelint instead.

  • Remove scss-lint checker. scss-lint depends on the dead Ruby Sass engine and is no longer maintained. Use scss-stylelint instead.

  • Remove eruby-erubis and eruby-ruumba checkers. Erubis has been abandoned since 2011 and Ruumba since 2020. ERuby support is removed.

  • Remove css-csslint checker. CSSLint has been abandoned since ~2017. Use css-stylelint instead.

  • Remove protobuf-prototool checker. Prototool was archived by Uber in March 2022.

  • Remove nix-linter checker. nix-linter has been abandoned by its author, who recommends statix instead.

  • Remove coffee-coffeelint checker. CoffeeLint has been effectively inactive with known security vulnerabilities.

  • Remove asciidoc checker. The legacy Python AsciiDoc processor is superseded by Asciidoctor. Use asciidoctor instead.

  • Remove json-jsonlint checker. The original jsonlint has been abandoned since ~2017. Use json-python-json or json-jq instead.

  • Remove xml-xmlstarlet checker. XMLStarlet has not had a release since 2014. Use xml-xmllint instead.

  • Remove javascript-jshint checker. JSHint has been largely superseded by ESLint. Use javascript-eslint instead.

  • Remove yaml-ruby checker. Ruby’s YAML parser provides the same functionality as js-yaml. Use yaml-jsyaml or yaml-yamllint instead.

  • Remove ruby-jruby checker. JRuby is extremely niche for linting. Use ruby-rubocop or ruby instead.

Changes

  • Remove dead code: flycheck-option-symbol, flycheck-flake8--find-project-root, flycheck-string-or-nil-p, flycheck-chunked-process-input and associated chunking functions.

  • Replace deprecated seq-contains with seq-contains-p.

  • Replace flycheck-string-or-nil-p with built-in string-or-null-p.

  • Use json-parse-buffer unconditionally (available since Emacs 27.1), removing the json-read fallback and the json library dependency.

  • Use libxml-available-p (available since Emacs 27.1) instead of fboundp check.

  • Use seq-sort-by (available since Emacs 27.1) instead of workaround.

  • Use seq-mapcat instead of (apply #'append (seq-map ...)).

  • Minor code style improvements: when (not ...) → unless, reverse → nreverse for locally-built lists.

  • [#2152]: Point package URL header to GitHub repository instead of the website.

35.0 (2025-04-23)

New Features

  • [#2105]: Add options for configuring the jsonnet checker.

  • [#1975]: Add support for --expt-relaxed-constexpr flag to cuda checker.

  • [#2055]: Add support for --expt-extended-lambda flag to cuda checker.

  • [#1987]: Add a flag flycheck-auto-display-errors-after-checking control whether to display errors automatically after checking.

  • [#2035]: Add colors to FlyC mode line and update mode line menu. Introduce flycheck-mode-success-indicator.

  • [#2059]: Enable checkers for new AUCTeX 14 modes.

  • [#2070]: Add a new syntax checker r for R with the builtin parse function.

  • [#2073]: Add new syntax checker salt-lint for the salt infrastructure-as-code language.

  • [#2071]: Add a new checker perl-perlimports, for cleaning up Perl import statements.

  • [#1972]: New defcustom flycheck-clear-displayed-errors-function to customize how error messages are to be cleared.

  • [#2075]: Add the flycheck-chktex-extra-flags option to the tex-chktex checker.

  • [#2107]: Add -Xcompiler option for cuda-nvcc.

  • Add new markdownlint-cli2 checker.

Bugs fixed

  • [#2057]: Revert the replacement of flycheck-version with lm-version.

  • [#1972]: Refine flycheck-display-errors lifecycle so error messages can be cleared.

  • [#2067]: Handle correctly GHC 9.6 error output format.

  • [#2079]: Fix ruff error-patterns and error-filter.

Changes

  • (Breaking) [#2066]: Remove support for versions of stylelint older than v14.

  • Update error-patterns for ghdl 4.1.0.

  • [#2078]: ruff: --output-format=text replaced with --output-format=concise due to upstream changes in ruff.

34.1 (2024-02-18)

Bugs fixed

  • [#2054]: Remove explicit dep on the built-in package seq.el.

34.0 (2024-02-14)

New Features

  • New syntax checkers

    • [#2015]: PHP with phpcs-changed

    • [#2017]: HAML with haml-lint

    • [#2030]: Add yaml-actionlint checker for GitHub yaml action workflows.

    • [#2052]: Sass with Stylelint

    • [#2013]: Nix with statix

    • [#1935]: Chef (Ruby) with cookstyle

    • [#1915]: Markdown with pymarkdown

  • [#1873]: Add error explainer to perl-perlcritic.

  • [#1875]: Add error-explainer to css-stylelint.

  • [#1876]: Add error-explainer for markdownlint checker.

  • [#2019]: Add support for RELAX NG schema in xmllint.

Bugs Fixed

  • [#1793]: Fix flycheck-ruby-rubocop on buffers with no backing file.

Changes

  • [#2026]: Update the possible locations for yamllint’s configuration file.

  • (Breaking) [#1697]: Remove the coq checker.

  • (Breaking) [#1935]: Remove the chef-foodcritic checker. (it’s now replaced by ruby-chef-cookstyle)

  • (Breaking) [#2018]: Remove the golint checker.

  • (Breaking) Remove the ruby-rubylint checker.

  • [#1704]: The tslint checker is deprecated; it will go away in a future release.

33.1 (2024-02-04)

  • Bugs Fixed

    • Fixed an usage of the removed flycheck--format-message function.

33.0 (2024-02-04)

Note

The changelog for this release is incomplete.

  • New features and improvements

    • The flycheck-verify-setup UI now includes buttons to re-enable manually disabled checkers and to try to re-enable automatically disabled checkers (command checkers are automatically disabled when their executable cannot be found). [GH-1755]

    • Error explainers can now return URLs (to show a webpage) or functions (to use custom formatting). For example, the Rust checker now renders explanations using markdown-view-mode. [GH-1753]

    • Enable checkers in many newer TreeSitter-based major modes (think *-ts-mode).

  • New syntax checkers

  • Breaking changes

    • Drop support for Emacs 25.

    • The variable flycheck-current-errors now contains errors in the order in which they were returned by checkers. In previous versions of Flycheck, this list was sorted by error position and severity. [GH-1749]

32 (frozen on May 3rd, 2020, released Mar 28, 2022)

  • Highlights

    • Many checkers and compiler, such as ocaml, rust, eslint, and others, include end-line and end-column information. Flycheck can now highlight the exact region that they report. Authors of checker definitions can use the new :end-line and :end-column arguments in flycheck-error-new, or the new end-line and end-column fields in error patterns. [GH-1400]

    • Errors that checkers return for other files will now be displayed on the first line of the current buffer instead of begin discarded. The error list indicates which file each error came from, and navigation moves automatically moves between files. This change helps with compiled languages, where an error in another file may cause the current file to be considered invalid. Variables flycheck-relevant-error-other-file-show and flycheck-relevant-error-other-file-minimum-level control this behavior. [GH-1427]

    • Flycheck can now draw error indicators in margins in addition to fringes. Margins can contain arbitrary characters and images, not just monochrome bitmaps, allowing for a better experience on high-DPI screens. flycheck-indication-mode controls this behavior, and flycheck-set-indication-mode can be used to automatically adjust the fringes and margins. Additionally, Flycheck’s will now use high-resolution fringe bitmaps if the fringe is wide enough [GH-1742, GH-1744]

    • Error highlighting is now configurable, using the new flycheck-highlighting-style variable: instead of applying level-dependent faces (typically with wavy underlines), Flycheck can now insert delimiters around errors, or mix styles depending on how many lines an error covers. Additionally, stipples are added in the fringes to indicate errors that span multiple lines. [GH-1743]

  • New features and improvements

    • Flycheck can now trigger a syntax check automatically after switching buffers, using the idle-buffer-switch option in flycheck-check-syntax-automatically. This is useful when errors in a file are due to problems in a separate file. Variables flycheck-idle-buffer-switch-delay and flycheck-buffer-switch-check-intermediate-buffers control the functionality. [GH-1297]

    • Flycheck will now use Emacs’ native XML parsing when libXML fails. This behavior can be changed by customizing flycheck-xml-parser. [GH-1349]

    • flycheck-verify-setup now shows more clearly which checkers will run in the buffer, and which are misconfigured. [GH-1478]

    • Flycheck now locates checker executables using a customizable function, flycheck-executable-find. The default value of this function allows relative paths (set e.g. in file or dir-local variables) in addition to absolute paths and executable names. [GH-1485]

    • Checkers that report error positions as a single offset from the start of the file can use the new flycheck-error-new-at-pos constructor instead of converting that position to a line and a column. [GH-1400]

    • Config-file variables can now be set to a list of file names. This is useful for checkers like mypy which don’t run correctly when called from a subdirectory without passing an explicit config file. [GH-1711]

    • Thanks to algorithmic improvements in error reporting, Flycheck is now much faster in large buffers. [GH-1750]

  • New syntax checkers:

  • Checker improvements:

    • python-pylint and python-flake8 are now invoked with python -c, to make it easier to change between Python 2 and Python 3. [GH-1113]

    • Add flycheck-perl-module-list to use specified modules when syntax checking code with the perl checker. [GH-1207]

    • rust-cargo now uses cargo check and cargo test. [GH-1289]

    • Add flycheck-ghc-stack-project-file for the haskell-stack-ghc checker. [GH-1316]

    • Add flycheck-cppcheck-suppressions-file to pass a suppressions file to cppcheck. [GH-1329]

    • Add --force-exclusion flag to rubocop command. [GH-1348]

    • Flycheck now uses ESLint’s JSON output instead of checkstyle XML. [GH-1350]

    • Add flycheck-eslint-args to pass arguments to javascript-eslint. [GH-1360]

    • Flycheck will now execute rubocop from the directory where a Gemfile is located. If a Gemfile does not exist, the old behaviour of running the command from the directory where .rubocop.yml is found will be used. [GH-1368]

    • Add flycheck-sh-bash-args to pass arguments to sh-bash. [GH-1439]

    • haskell-stack-ghc will not try to install GHC anymore. [GH-1443]

    • Add flycheck-ghdl-ieee-library to select which standard IEEE library to use for ghdl. [GH-1547]

    • The javascript-eslint checker now supports typescript-mode by default.

    • Add flycheck-erlang-rebar3-profile to select which profile to use when compiling erlang with rebar3. [GH-1560]

    • Add flycheck-relevant-error-other-file-show to avoid showing errors from other files. [GH-1579]

    • The nix-linter checker now has an error explainer. [GH-1586]

    • The Emacs Lisp checker can now run in buffers not backed by files. [GH-1695]

  • Breaking changes

    • Remove the javascript-jscs checker. [GH-1024]

    • Remove the elixir-dogma checker. [GH-1450]

    • rust-cargo now requires Rust 1.17 or newer. [GH-1289]

    • rust now requires 1.18 or newer. [GH-1501]

    • Rename flycheck-cargo-rustc-args to flycheck-cargo-check-args. [GH-1289]

    • rust-cargo does not use the variable flycheck-rust-args anymore. [GH-1289]

    • Improve detection of default directory for haskell-ghc to consider hpack project files. [GH-1435]

    • Replace go tool vet with go vet. [GH-1548]

    • Remove the deprecated go-megacheck checker, which is replaced by go-staticcheck. [GH-1583]

31 (Oct 07, 2017)

  • Breaking changes

    • rust-cargo now requires Rust 1.15 or newer [GH-1201]

    • Remove javascript-gjslint checker

  • New syntax checkers:

  • New features:

    • Add flycheck-xml-xmlstarlet-xsd-path and flycheck-xml-xmllint-xsd-path to specify an XSD schema to validate XML documents against [GH-1272]

    • Add flycheck-tslint-args to pass additional arguments to tslint [GH-1186]

    • Add an error explainer to the rpm-rpmlint checker using rpmlint -I [GH-1235]

    • Add flycheck-emacs-lisp-check-declare to check function declaration in the emacs-lisp checker [GH-1286]

    • Add flycheck-shellcheck-follow-sources to check included files when using the sh-shellcheck checker [GH-1256]

  • Improvements:

    • Use option flycheck-go-build-tags for go-test, go-vet and go-errcheck as well.

    • Add a revert function to flycheck-verify-setup, so hitting g reloads the buffer.

    • Make sure the erlang compiler is only run on compilable files.

    • flycheck-tslint does not crash any more on deprecation notices [GH-1174]

    • rust-cargo now checks integration tests, examples and benchmarks [GH-1206]

    • rust-cargo does not use flycheck-rust-library-path anymore, as dependencies are taken care of by Cargo [GH-1206]

    • c/c++-gcc checker now works from GCC 4.4 and up [GH-1226]

30 (Oct 12, 2016)

  • Breaking changes

    • Flycheck now requires flake8 3.0 or newer

    • Remove --config option in lua-luacheck in favour of luacheck’s own .luacheckrc detection. Therefore flycheck-luacheckrc is no longer used [GH-1057]

    • :modes is now mandatory for syntax checker definitions [GH-1071]

    • Remove jade checker [GH-951] [GH-1084]

    • Remove javascript-eslintrc and instead rely on eslint’s own configuration file search [GH-1085]

    • C-c ! e explains errors now [GH-1122]

  • New syntax checkers:

  • New features:

    • Add flycheck-cargo-rustc-args to pass multiple arguments to cargo rustc subcommand [GH-1079]

    • Add :error-explainer to flycheck-define-checker and flycheck-explain-error-at-point to display explanations of errors [GH-1122]

    • Add an error explainer to the rust and rust-cargo checkers using rustc --explain [GH-1122]

    • Add :enabled property to flycheck-define-checker [GH-1089]

  • Improvements:

    • Do not use javascript-eslint if eslint cannot find a valid configuration [GH-1085]

    • Automatically disable syntax checkers which are not installed instead of checking executable before each syntax check [GH-1116]

    • Add patterns for syntax errors to scheme-chicken [GH-1123]

29 (Aug 28, 2016)

  • Breaking changes

    • Change flycheck-eslint-rulesdir (string) to flycheck-eslint-rules-directories (list of strings) [GH-1016]

    • Require rust 1.7 or newer for rust and rust-cargo [GH-1036]

  • New syntax checkers:

  • New features:

    • Add :working-directory option to flycheck-define-command-checker [GH-973] [GH-1012]

    • flycheck-go-build-install-deps turns on dependency installation for go test as well as go build [GH-1003]

  • Improvements:

    • Add default directory for haskell-stack-ghc and haskell-ghc checkers [GH-1007]

    • rust and rust-cargo checkers now support the new error format of rust 1.12 [GH-1016]

    • flycheck-verify-checker and flycheck-verify-setup now include information about configuration files of syntax checkers [GH-1021] [GH-1038]

28 (Jun 05, 2016)

  • Breaking changes:

    • Rename luacheck to lua-luacheck to comply with our naming conventions

    • Remove flycheck-cppcheck-language-standard in favour of flycheck-cppcheck-standards which is a list of standards [GH-960]

  • New features:

    • Add option to set binary name for rust-cargo [GH-958]

    • Add flycheck-cppcheck-standards to pass multiple code standards to cppcheck [GH-960]

    • Add flycheck-cppcheck-suppressions to suppress warnings for cppcheck [GH-960]

  • Improvements:

    • Check Racket syntax in Geiser Mode [GH-979]

  • Bug fixes

    • Do not signal errors when tslint reports no output [GH-981]

    • Do not generate invalid temporary filenames on Windows [GH-983]

27 (May 08, 2016)

26 (Apr 27, 2016)

Flycheck now has a Code of Conduct which defines the acceptable behaviour and the moderation guidelines for the Flycheck community. [GH-819]

Flycheck also provides a Gitter channel now for questions and discussions about development. [GH-820]

The native Texinfo manual is again replaced with a Sphinx based documentation. We hope that this change makes the manual easier to edit and to maintain and more welcoming for new contributors. The downside is that we can not longer include a Info manual in Flycheck’s MELPA packages.

From this release onward Flycheck will use a single continuously increasing version number. Breaking changes may occur at any point.

  • Breaking changes:

    • Remove flycheck-copy-messages-as-kill, obsolete since Flycheck 0.22

    • Remove flycheck-perlcritic-verbosity, obsolete since Flycheck 0.22

    • Replace flycheck-completion-system with flycheck-completing-read-function [GH-870]

    • JSON syntax checkers now require json-mode and do not check in Javascript Mode anymore

    • Prefer eslint over jshint for Javascript

    • Obsolete flycheck-info in favour of the new flycheck-manual command

  • New syntax checkers:

  • New features:

    • Add flycheck-puppet-lint-rc to customise the location of the puppetlint configuration file [GH-846]

    • Add flycheck-puppet-lint-disabled-checks to disable specific checks of puppetlint [GH-824]

    • New library flycheck-buttercup to support writing Buttercup specs for Flycheck

    • Add flycheck-perlcriticrc to set a configuration file for Perl::Critic [GH-851]

    • Add flycheck-jshint-extract-javascript to extract Javascript from HTML [GH-825]

    • Add flycheck-cppcheck-language-standard to set the language standard for cppcheck [GH-862]

    • Add flycheck-mode-line-prefix to customise the prefix of Flycheck’s mode line lighter [GH-879] [GH-880]

    • Add flycheck-go-vet-shadow to check for shadowed variables with go vet [GH-765] [GH-897]

    • Add flycheck-ghc-stack-use-nix to enable Nix support for Stack GHC [GH-913]

  • Improvements:

    • Map error IDs from flake8-pep257 to Flycheck error levels

    • Explicitly display errors at point with C-c ! h [GH-834]

    • Merge message and checker columns in the error list to remove redundant ellipsis [GH-828]

    • Indicate disabled checkers in verification buffers [GH-749]

    • Do not enable Flycheck Mode in fundamental-mode buffers [GH-883]

    • Write go test output to a temporary files [GH-887]

    • Check whether lintr is actually installed [GH-911]

  • Bug fixes:

    • Fix folding of C/C++ errors from included files [GH-783]

    • Fix verification of SCSS-Lint checkstyle reporter

    • Don’t fall back to rust if rust-cargo should be used [GH-817]

    • Don’t change current buffer when closing the error message buffer [GH-648]

    • Never display error message buffer in current window [GH-822]

    • Work around a caching issue in Rubocop [GH-844]

    • Fix checkdoc failure with some Emacs Lisp syntax [GH-833] [GH-845] [GH-898]

    • Correctly parse Haskell module name with exports right after the module name [GH-848]

    • Don’t hang when sending buffers to node.js processes on Windows [GH-794][GH-850]

    • Parse suggestions from hlint [GH-874]

    • Go errcheck handles multiple $GOPATH entries correctly now [GH-580][GH-906]

    • Properly handle Go build failing in a directory with multiple packages [GH-676] [GH-904]

    • Make cppcheck recognise C++ header files [GH-909]

    • Don’t run phpcs on empty buffers [GH-907]