If you have previously installed the MASS libraries on the system on which you are installing the IBM® XL C/C++ for AIX®, V11.1, it is recommended that you uninstall the libraries by removing the directory in which they have been installed.
To remove the MASS directory, enter:
rm -rf mass_directory
where mass_directory is the location of the MASS libraries. If you have created symbolic links in the /usr/lib/ directory to the libraries in the MASS directory, you must delete them as well. The compiler installation automatically handles the creation of the necessary symbolic links.