The key to understanding what the problem is here is the message "Can't open shared lib /tools/idea..." Gen_sch8 is a dynamically linked program, and when it is linked, all references through environment variables (e.g., $MGC_HOME and $LD_LIBRARY_PATH/$SHLIB_PATH) get resolved to hard pathnames (e.g., /tools/idea). When gen_sch8 is run at a user's installation, the odds are that his or her network will not be configured exactly like Xilinx's, hence any references to /tools/idea will not be resolvable, yielding error messages like the one above.
For Gen_sch8 or any program which references any Mentor shared runtime libraries to work properly, the LD_LIBRARY_PATH/SHLIB_PATH variable must be set to include the hard pathname to them. This can be done easily, simply by sourcing the Mentor set_mgc_env script found in $MGC_HOME/bin prior to running Gen_sch8 in the same shell. In order to make this operation transparent, we include a Gen_sch8 Bourne shell script in $LCA/com/hppa which sources set_mgc_env prior to invoking the Gen_sch8 program found in $LCA/bin/hppa. This will always work fine as long as $LCA/com/hppa appears ahead of $LCA/bin/hppa in your path. This is why the "com" directory must also be listed before the "bin" directory in your executable path.