To my understanding, USE flags should modify minor aspects of the package behavior. "win64" flag of wine is different: 1. wine64 is not capable of running x86 application 2. wine64 will tag .wine user directory as "win64", essentially breaking it and forcing user to reinstall everything Reproducible: Always Steps to Reproduce: Emerge app-emulation/wine with win64 flag set. Expected Results: Considering the above, I would like to suggest that wine64 will be set as a separate ebuild, mutually exclusive with wine32 and carrying the appropriate warning. Better solution will be something akin to multilibs approach, whereupon two versions of wine are built and installed in different locations with distinctive default path names.
*** This bug has been marked as a duplicate of bug 296608 ***