> But the problem is, i am expecting the program to do it automatically.
PATH is a user environment variable. I haven't seen any program installation modify that var. And that's a good thing. I haven't used choosenim (as it doesn't work on my OS), but may be it should display something like "nim binary is installed at /foo/bar/bin/", and that the user should add that to their path themselves. See how PATH update instructions are added to Go installation too.
