Reducing Cargo target directory size with -Zno-embed-metadata

Disk usage of the target directory is a commonly cited annoyance with Rust (and Cargo) – in the last year’s Annual Survey, it was the third most pressing issue of Rust users, right after slow compilation and subpar debugging experience. Given the “build everything from source” compilation model of Rust, and both debuginfo and incremental compilation being enabled by default in the dev Cargo profile, it is unlikely that the target directory will ever become lean and small. However, there are still ways of how we could reduce the target directory size by a non-trivial amount. I will describe a brand-new method of achieving that in this blog post. Note that there are also initiatives to reduce the size of the target directory along the temporal axis, i.e. prevent it from ballooning over time (see Cargo Garbage Collection). This post is more about how to reduce the size of the target directory overall. What takes up the space, anyway? It is not the focus of this post to dive deep into e ... Read full article.