[Usage problem] How to download the source code of external deps of rust std #2644

Hey there, thanks a lot for reading this issue.
I am one novice of rust. When I learn the rust, I found one problem that I can not navigate into the external deps of rust std code.

what is the problem

for example, I wanna know how Hashmap implemented. So I use Clion to read the source code std lib. And I found the std relies on the external dep called hashbrown, which I couldn't navigate into it to read more:

what I found

I found the deps that std relies on are imported in the way called rustlib which are all stored under .rustup:

what I wanna know

So, what I wanna know is that is there any way to use rustup to download the source code of rlib or make it possible to read the source code of deps of std lib?

I would appreciate it if anyone can offer the help. Thanks a lot for your reading.