arcanist's linter module for cppcheck needs php56-dom package.

This misleading exception appears which you can simply fix by installing the missing PHP package.


[2015-09-17 14:20:14] EXCEPTION: (PhutilAggregateException) Some linters failed:
    - PhutilMissingSymbolException: Failed to load class or interface 'DOMDocument': the class or interface 'DOMDocument' is not defined in the library map for any loaded phutil library. If this symbol was recently added or moved, your lib
rary map may be out of date. You can rebuild the map by running 'arc liberate'. For more information, see: http://www.phabricator.com/docs/phabricator/article/libphutil_Libraries_User_Guide.html at [<arcanist>/src/lint/engine/ArcanistLintE
ngine.php:273]
arcanist(), phutil()
  #0 <#2> __phutil_autoload(string) called at [<phutil>/src/__phutil_library_init__.php:25]
  #1 <#2> spl_autoload_call(string) called at [<arcanist>/src/lint/linter/ArcanistCppcheckLinter.php:73]
  #2 <#2> ArcanistCppcheckLinter::parseLinterOutput(string, integer, string, string) called at [<arcanist>/src/lint/linter/ArcanistExternalLinter.php:355]
  #3 <#2> ArcanistExternalLinter::resolveFuture(string, ExecFuture) called at [<arcanist>/src/lint/linter/ArcanistFutureLinter.php:34]
  #4 <#2> ArcanistFutureLinter::didLintPaths(array) called at [<arcanist>/src/lint/engine/ArcanistLintEngine.php:600]
  #5 <#2> ArcanistLintEngine::executeDidLintOnPaths(ArcanistCppcheckLinter, array) called at [<arcanist>/src/lint/engine/ArcanistLintEngine.php:551]
  #6 <#2> ArcanistLintEngine::executeLintersOnChunk(array, array) called at [<arcanist>/src/lint/engine/ArcanistLintEngine.php:479]
  #7 <#2> ArcanistLintEngine::executeLinters(array) called at [<arcanist>/src/lint/engine/ArcanistLintEngine.php:217]
  #8 ArcanistLintEngine::run() called at [<arcanist>/src/workflow/ArcanistLintWorkflow.php:331]
  #9 ArcanistLintWorkflow::run() called at [<arcanist>/scripts/arcanist.php:382]

--
Thanks
Martin