The rest of the world handles that through PATH/PATH equivalent.
Either the package manager is invoked with a different PATH (one that contains the desired Node/Java/whatever version as a higher priority item than any other version on the system).
Or the package manager itself has some way to figure that out through its config file.
Or there is a package manager launch tool, just like pyenv or whatever, which does that for you.
In practice it's not that a big of a deal, even for Maven, a tool created 21 years ago. As the average software dev you figure that stuff out a few weeks into using the tool, maybe you get burnt a few times early on for misconfiguring it and then you're on autopilot for the rest of your career.
Wait till you hear about Java's CLASSPATH and the idea of having a SINGLE, UNIFIED package dependency repo on your system, with no need for per-project dependency repos (node_modules), symlinks, or all of that stupidity.
CLASSPATH was introduced by Java in 1996, I think, and popularized for Java dependency management in 2004.
> The rest of the world handles that through PATH/PATH equivalent.
Activating a venv is just setting a few environment variables, including PATH, and storing the old values so that you can put them back to deactivate the environment.
It's also putting dependencies in a certain folder in a setup that isn't even portable between machines. Probably some other stuff I'm forgetting.
Well, that is how Python does it as well, an venv is a script setting the PYTHONPATH.
This is wrong. A venv is a hierarchy of folders containing a config file, as well as some symlinks to Python (or stub executables on Windows). "How Python does it" is that when it starts up from the symlink, it looks for the config file at a relative path; if that checks out, it uses hard-coded rules to add another relative path to sys.path. PYTHONPATH is never involved.
The venvs created by the standard library `venv`, as well as by uv (and by the third-party `virtualenv` that formed the original basis for `venv`), also happen to include "activation" scripts that manipulate some environment variables. PYTHONPATH is not among these. It manipulates PATH, so that the venv's symlink is on the path. And it may unset PYTHONHOME.