Question

I am attempting to work locally on a PHP application which I cloned from the Git repository my partner and I use.

He uses a Mac, and until now I have been working on the app in a virtual Ubuntu Linux environment. Both environments have been able to use Compass polling with the same file structure and files.

On Windows 7, I run Compass commands from Cygwin, and this is the command I use to have Compass poll from the root directory of the app (C:/wamp/www/application):

compass watch --trace src/Application/ApplicationBundle/Resources/compass/

When I then make a change to a .scss file, I receive the following error:

ArgumentError on line 716 of /usr/lib/ruby/1.8/pathname.rb: different prefix: "/
/cygdrivecwampwwwlimelightsrclimelightlimelightbundleresourcescompasssrcpartials
_object.scss" and "/cygdrive/c/wamp/www/limelight/src/limelight/limelightbundle/
resources/compass/src"
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/path.rb:81:in 'split_path'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/path.rb:69:in 'run_callback'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/path.rb:55:in 'callback_action'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/path.rb:35:in 'update'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/state/directory.rb:39:in 'modified'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/state/directory.rb:37:in 'each'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/state/directory.rb:37:in 'modified'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/state/directory.rb:18:in 'refresh'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/backends/polling.rb:17:in 'run'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/backends/polling.rb:17:in 'each'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/backends/polling.rb:17:in 'run'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/backends/polling.rb:15:in 'loop'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/backends/polling.rb:15:in 'run'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm/monitor.rb:26:in 'run'
/usr/lib/ruby/gems/1.8/gems/fssm-0.2.7/lib/fssm.rb:20:in 'monitor'
/usr/lib/ruby/gems/1.8/gems/compass-0.11.1/lib/compass/commands/watch_project.rb:86:in 'perform'
/usr/lib/ruby/gems/1.8/gems/compass-0.11.1/lib/compass/commands/base.rb:18:in 'execute'
/usr/lib/ruby/gems/1.8/gems/compass-0.11.1/lib/compass/commands/project_base.rb:19:in 'execute'
/usr/lib/ruby/gems/1.8/gems/compass-0.11.1/lib/compass/exec/sub_command_ui.rb:43:in 'perform!'
/usr/lib/ruby/gems/1.8/gems/compass-0.11.1/lib/compass/exec/sub_command_ui.rb:15:in 'run!'
/usr/lib/ruby/gems/1.8/gems/compass-0.11.1/bin/compass:25
/usr/lib/ruby/gems/1.8/gems/compass-0.11.1/bin/compass:39:in 'call'
/usr/lib/ruby/gems/1.8/gems/compass-0.11.1/bin/compass:39
/usr/bin/compass:19:in 'load'
/usr/bin/compass:19

All I’ve been able to find through searching is that it may have something to do with the fact that Windows capitalizes its drive names, although the lack of slashes in the returned path makes me think the problem may be elsewhere.

Does anyone know why I might receive this error in Windows, but not other platforms?

NOTE: I have found a work-around involving installing ruby (and compass) through Windows’ command prompt rather than Cygwin, and that should work fine for now. Still, if anyone has ideas, I’m still curious as to what the problem could be.

Answer 1

According to this commit, this is a problem caused by a compass dependency called FSSM. It is used to monitor file changes in compass. A workaround is described in this comment.

It seems that FSSM detects that ruby is running inside a Windows box, and treats paths in the Windows’ way (C:\blabla). Commenting out the line 26 of the file <fssm_gem_path>/lib/fssm/pathname.rb makes compass watch work as expected. You can also add

unless path[0, 1] == File::SEPARATOR

to the end of line 26 to make it work.