Ever since my first Linux experience, where /usr actually contained way more useful tools by default than other systems, this has been a double-edged sword. Al

Ever since my first Linux experience, where /usr actually contained way more useful tools by default than other systems, this has been a double-edged sword. All the convenience of autoconf and default behaviors, etc. goes far out the window when /usr/lib is ever so slightly too old. It’s kind of a curse. The virtualenv concept makes more sense: set a default on day 1 but assume you’ll want a new foundation periodically. When the foundations themselves are versioned, you can evolve your environment to some degree without having a completely chaotic mix of the latest updates.