One that that I'm not able to tell from the proposal: is the /v1 at the end of an import path a magical value that the tool handles, or do I literally need to h

One that that I'm not able to tell from the proposal: is the /v1 at the end of an import path a magical value that the tool handles, or do I literally need to have that directory in my repo and have a version history represented at the top level of every project? Why not do the symbol mangling in the compiler if the goal is to have multiple simultaneous versions built in? This is easy to make backward compatible since it could default to v1.