Cargo seems to download the same crate at least once per package

[cuviper]

The downloads should be shared from ~/.cargo/registry/cache, as long as you're not setting CARGO_HOME to something else.

The build artifacts in each project's target/ directory are a different story, and that's probably what's eating so much of your space. You can see some discussion in this other thread:

[Idea] Cargo Global Binary Cache

Motivation I am currently use Rust for almost every thing, including developing software and data analysis. And Rust works pretty well. But Cargo is annoying for building dependencies separately. This is very annoying because: It slow down the build. Even a small project may spend a long time to build even with full parallelization. For my use case, I write a lot of data analyzing script/Adhoc projects with Rust. It blows up my disk space really quickly. When I need to clean the code or build …