Due to a problem in the Quartus® II software versions 11.0 SP1 and earlier, you may see the following warning when generating a Qsys system on a Linux machine without the en_US locale installed:
>perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = (unset), LC_CTYPE = "en_US", LANG = "C" are supported and installed on your system. perl: warning: Falling back to the standard locale ("C")/ Failed to generate module <module name>
To resolve this issue, as an adminitrator, install the locale with the following command:
sudo locale-gen en_US
This issue is scheduled to be fixed in a future version of the Quartus II software.