rt。很好奇。[I'm curious about it.]
Raco is a tool that's part of a racket distribution that helps manage packages for that distribution. Conceptually, I think of it as being "below" racket, rather than above it. I think this is analogous to the Node/JavaScript situation, where you have the node package manager, npm, that manages packages, but also the node version manager, nvm, that actually manages installations of node itself. I believe that ocaml is in a similar situation.
It certainly seems like it would be possible for raco to do something like this, but (in my mind) it would significantly increase the conceptual tangling and opportunity for error. I could also see creating a tool such as nvm or ocaml's whatever-its-called that performs this task, but I'm certainly not volunteering to create it :). Currently, I'm a big fan of the fact that a racket installation can live in a single directory, and that it's possible to have a whole bunch of parallel installations. As I write this, I realize that my position as racket release manager probably makes this more attractive :).
ObJapanese: after one full year of Duolingo Japanese, I can now recognize exactly ONE glyph of the above, which is 新. "new"! Ah well.
感谢你的回复！这让我更深刻地理解了 raco 的设计目标 [Thanks for your response. Now I understand the design philosophy of raco deeper.]