You don't need to expunge c89 from gcc for progress to have happened - we've got c99 and c11 and whatever c17 is or isn't already there. Effectively, however,

You don't need to expunge c89 from gcc for progress to have happened - we've got c99 and c11 and whatever c17 is or isn't already there. Effectively, however, python2 and python3 are different languages. Since they're interpreted, there's now a problem with '#!/usr/bin/env python' in your script: which python version is being invoked? Which language version are modules targeting? It's a mess. But the poster child for screwing up a language version upgrade is still Perl.