Why not have a central directory to store all the built crates?

[ohsayan]

Cargo creates a copy of the dependencies for every project built. Let's say I was using the rand crate. If I created a project called rand_super and rand_awesome then both of the projects would be given their own copies of rand. So why don't we create some kind of central directory for the already downloaded crates, let's say we have ~/.rustup/crates.io/crates/ or something like that and we store all the deps that are downloaded. Then it doesn't need to be downloaded for each project individually. And we can have a command like cargo add <http://url/to/crate>. The crate URL can simply be the crates.io URL say for rand it could be something like cargo add https://crates.io/crates/rand/0.6.5/. This would be a great advantage. I'll work on this and try to create an experimental version of cargo with this feature. Thoughts?

[dwijnand]

Configuring the target directory for built crates is already implemented. This is a duplicate of #482, which has been implemented.

See

• https://doc.rust-lang.org/cargo/reference/environment-variables.html
• https://doc.rust-lang.org/cargo/reference/config.html
• https://stackoverflow.com/questions/37471391/can-i-prevent-cargo-from-rebuilding-libraries-with-every-new-project; and
• https://stackoverflow.com/a/37472558/463761

for more info and thoughts on this.