Jun 12, 2014 — Flycheck 0.19 released

We are pleased to announce the release of Flycheck 0.19.

Breaking changes

ruby-rubylint requires Ruby Lint 2.0 or newer, due to some breaking changes in the command line interface of Ruby Lint.



The new flycheck-cppcheck-inconclusive enables c/c++-cppcheck tests that might yield false positives.

When reporting errors in included files, c/c++-clang now includes the error messages in the faulty include file in the error message on the affected #include statement.

Emacs Lisp

Flycheck now removes redundant whitespace in the error messages reported by the emacs-lisp syntax checker.


Go code is now checked for unhandled error return values with the new go-errcheck syntax checker.

Flycheck does not longer signal errors in Go Mode, when the go executable is not available.


Flycheck now dedents the error messages reported by haskell-ghc, and properly checks Haskell files without extensions.


rust has a new flycheck-rust-check-tests option, to disable syntax checking of test code.

New features

Syntax checkers may now use the :error-filter argument to flycheck-define-checker to apply a function to all errors after parsing. The function is given the list of parsed errors, and shall return the list of errors that Flycheck is to use as the result of the syntax checker. It may modify the list and all error objects therein in-place.

The new option flycheck-keymap-prefix lets you change the prefix key used by Flycheck. The default is still C-c !.


The Flycheck manual assumes that you are using the default prefix key. You are encouraged to leave the prefix key unchanged, and instead add your own custom bindings to the Flycheck key map:

(eval-after-load 'flycheck
  '(define-key flycheck-mode-map (kbd "<f8>") #'flycheck-list-errors))

Likewise, you now can configure the prefix of in-place temporary files created by Flycheck with flycheck-temp-prefix.


Changing the prefix may break syntax checkers. In doubt, stick to the default prefix.

Bug fixes

Flycheck now correctly kills running process and removes the temporary files when stopping a syntax check or killing the buffer.

Also, Flycheck does not long warn if a syntax checker only reports errors for other files.

Misc changes

Flycheck now has an official logo, and its own mail address. You can see both on the Github profile of the Flycheck project.