Getting a "QFont::setPixelSize: Pixel size <= 0 (0)" Warning Message

[cameronkendall]

When running tests I get the following warning message:

QFont::setPixelSize: Pixel size <= 0 (0)

Is there a way to hide/suppress this? I don't even know what it represents, and Its showing up every time I run the tests.

I'm using QT 4.8.4 on Mac OS 10.7.5

Gemfile:

group :development do
  gem 'guard-minitest', '0.5.0'
  gem 'rb-fsevent', '0.9.3'
  gem 'growl', '1.0.3'
  gem 'launchy'
  gem 'capybara-webkit', '0.14.2'
end

group :test do
  gem 'minitest', '4.6.2'
  gem 'capybara', '2.0.2'
  gem 'database_cleaner', '0.9.1'
  gem 'factory_girl_rails', '4.2.1'
end

[jferris]

There was some discussion about this on the mailing list that fizzled out: https://groups.google.com/forum/?fromgroups=#!topic/capybara-webkit/n1xMK0HnMWo

I think it's an issue in Qt and we could silence it by filtering debug output with qInstallMsgHandler.

[aminariana]

I get the same warning. Not the slightest hint about what it means.

[jaredbeck]

I get the same warning (and others) with an old capybara-webkit, testunit, and ruby 1.8.7, which seems to support @jferris suggestion that "it's an issue in Qt".

$ bundle exec rake test:integration
Started
.......QFont::setPixelSize: Pixel size <= 0 (0)
libpng warning: Unknown iTXt compression type or method
content-type missing in HTTP POST, defaulting to application/x-www-form-urlencoded. Use QNetworkRequest::setHeader() to fix this problem.
....................
Finished

$ ruby --version
ruby 1.8.7 (2012-10-12 patchlevel 371) [i686-darwin12.2.0]
$ grep capy Gemfile.lock 
  remote: git://github.com/thoughtbot/capybara-webkit.git
    capybara-webkit (0.13.0)
      capybara (>= 1.0.0, < 1.2)
    capybara (1.1.4)
  capybara (~> 1.1)
  capybara-webkit!

[petRUShka]

I have several types of warnings:

1. QFont::setPixelSize: Pixel size <= 0 (0)
2. content-type missing in HTTP POST, defaulting to application/x-www-form-urlencoded. Use QNetworkRequest::setHeader() to fix this problem.

[santry]

@petRUShka regarding the content-type error see rails/jquery-ujs#301

[petRUShka]

@santry, thanks for noticing that. What about first type of warnings?

[bundacia]

+1. I'm getting these same "QFont::setPixelSize: Pixel size <= 0 (0)" warnings as well.

[mcmire]

Here is the issue in the Qt JIRA. This issue seems to have been closed and fixed in QtWebkit instead. But that happened a couple years ago (after Qt 4.8.0 but before 4.8.4 which is the current 4.8.x release). It also appears that Qt 4.8.x might be using QtWebkit 4.9.4. Now whether or not 4.9.4 includes this bugfix, I don't know, but I would suspect at this point it does. So this is strange...

[ksweetie]

It seems to have been fixed in QtWebkit more recently too...

[jaredbeck]

Does capybara-webkit constrain the QtWebkit version at all? There is no such constraint in the .gemspec. I have no idea how dependencies are managed in C++. All I see is an #include <QtWebKit>. There is also a QTWEBKIT_VERSION_STR but I'm not seeing it used in any conditionals.

[mhoran]

@jaredbeck, see #529.

[jaredbeck]

It looks like PR #529 includes a preprocessor directive that constrains Qt >= 4.8.0. So it seems that a constraint is possible. However, I think it's safe to assume we don't want to constrain Qt just to fix a warning message, however annoying. Therefore, I think we can close this issue and recommend that people update their Qt?

[rebelwarrior]

I installed QT this past weekend through homebrew on a OSX 10.6.8 and I get the same error.

[Linuus]

I installed qt today through homebrew and also get the same message. On OSX Lion.

[stefanhendriks]

Same error here with QT 4.8.4 on OSX 10.8.4. The warning message is pretty large, so I am supressing it now in my tests although I'd prefer to have no warning at all.

[joshuaswilcox]

@stefanhendriks how did you suppress this in your tests? Thanks!

[pbrisbin]

FYI: Arch just got qt5-webkit 5.1 and the messages are no longer appearing.

[stefanhendriks]

@joshuaswilcox we basically have a class that overrides a method that writes messages. We collect them and print them after all tests are ran (we run dump_warnings ourselves at the end). Here some code:

FYI, what i did was basically cut off the warning (in dump_warnings) at 255 characters orso.

class WarningSuppressor

        SUPPRESS_THESE_WARNINGS = [
            'QFont::setPixelSize: Pixel size <= 0 (0)',
            'content-type missing in HTTP POST, defaulting to'
        ]

        class << self
          def write(message)
            if suppress_warning? message
              0
            else
              @warnings ||= []
              @warnings << message
              message.length
            end
          end

          def dump_warnings
            if @warnings
              puts
              puts "Warnings from QT while running specs:"

              @warnings.each do |warning|
                puts warning
              end
            end
          end

          private

          def suppress_warning? message
            SUPPRESS_THESE_WARNINGS.any? { |suppressable_warning| message.try(:strip).try(:include?, suppressable_warning) }
          end
        end
      end

      Capybara.register_driver :webkit do |app|
        Capybara::Webkit::Driver.new(app, stderr: WarningSuppressor)
      end

[Fjan]

@stefanhendriks Thanks! that warning has been bugging me for months. I didn't know realise was that easy to filter. Simply erasing it from the output stream is good enough for me though.

class WarningSuppressor
  class << self
    def write(message)
      puts(message) unless message =~ /QFont::setPixelSize: Pixel size <= 0/
      0
    end
  end
end

[joshuaswilcox]

@stefanhendriks and @Fjan, sorry for the naivety, but where did you put your custom class?

[Fjan]

@joshuaswilcox Doesn't really matter, you would probably put it in the same file where you use it, typically test_helper.rb

[joshuaswilcox]

@Fjan perfect, thanks!

[joshuaswilcox]

@Fjan sorry to be a bother, but I added this to a test_helper.rb and required it in my controller_name_spec.rb, but it still prints out. Not sure what I am missing? Thanks very much

[joshuaswilcox]

@Fjan yeah here is my spec_helper.rb

Capybara.default_driver = :webkit
Capybara.javascript_driver = :webkit
Capybara.default_wait_time = 5
Capybara.register_driver :webkit do |app|
  Capybara::Webkit::Driver.new(app, stderr: WarningSuppressor)
end

[Fjan]

@joshuaswilcox Sorry, I don't know. This is not a good place for general Ruby questions, please try stack overflow

[rebelwarrior]

@Fjan shouldn't that if be an unless? When I run it w/ the if I get the error displayed still.

[Fjan]

@rebelwarrior @joshuaswilcox You're right! I modified a line to remove some stuff that wasn't relevant here and I ended up reversing the condition. Sorry about that.
(PS. fixed the original snippet to avoid confusing other people)

[joshuaswilcox]

Bingo, Thought I was going crazy. Thanks all. @Fjan @rebelwarrior

[mhoran]

Closing this out. We've done just about all we can in capybara-webkit to silence these issues. Anyone who is still experiencing issues should:

1. Update Qt to the latest version (currently 5.3).
2. Ensure that they have not installed a debug version or compiled with the debug option.

[EXboys]

I use Pyqt and who who has solution.