Warning: filemtime(): stat failed - due to symlink?

I am also having this issue in Acquia's Cloud. I am guessing since both are distributed file systems, it is something to do with that symbolic link of the sites/[dir] and how LESS CSS module stores the directory name. Subscribing.

Update: I just tested adding the stylesheet via stylesheets[all][]='css/global.css.less' instead of using Omega's css[] specification, and that worked across the distributed system with the symlink. The problem with using that method for anything but debugging purposes is that you will mess up the order of aggregation for the stylesheets, effectively nullifying the global stylesheet's usefulness.

I also noted that there is a similar issue with Omega and the symlink regarding the upload of custom branding elements (logo, etc.) which leads me to believe the issue lies within how the Omega 3.x theme saves the local file directory. I'd recommend someone shift this over to that issue queue instead.

Sorry for the bad news.

Update 2: So there is an unbelievably simple fix for this. Check the file system settings *doh*, when you are on your local machine, if you set it to point to where the symlink points to (sites/sample -> sites/default, set the system settings to sites/default/files), your local installation will pick up the symbolic link effectively for everything except filestorage, and your remote system will be pointing the appropriate directory across the distributed format.

I feel very sheepish.

I'm not sure to the exact nature of the problem that you guys are experiencing, but I do know that they have been problems in the past with recursive directory generation used for file paths.

This has been removed in 7.x-4.x since source maps are now supported, and the file path is added as a src attribute to the <link /> tag.

All files are saved in 1 directory that should only get generated once.

This will remove several issues with cache flushes and regeneration of compiled files.

If either of you have some time, could you please try the 7.x-4.x branch and let me know if this resolves your issues?

I'll stand up a new site on Acquia's cloud following the same formation (default directory, symlink directory pointing to default directory) and give it a whirl with the new 4.x-dev. Stay tuned.