This issue is a temporary workaround. The actual fix is found here:
The issue is:
When compiling portlets or themes, when css is being compiled, the compiler is scanning all files in the drive rather than just the base directory of your portlet. In doing so, if you have any symbolic links in your filesystem, there's the chance that you can create an infinite loop during the css scan.
You'll get an error that's similar to this:
skipping symbolic link /sys/class/tty/console/subsystem/console/subsystem/tty9/subsystem/tty5/subsystem/console/subsystem/tty0/subsystem – too many levels of symbolic links.
This issue exists in versions of 6.1.30 and back. With this fix, plugins should now by default scan just the portlet folder you're compiling against.