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How I Reduced My Compile Times by 50% with Rust’s Incremental Compilation Magic
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For any developer who has worked with large codebases, long compile times can feel like an unavoidable annoyance. You know the drill: make a tiny change, hit compile, then go grab a coffee (or two). Even with Rust’s famously fast compiler, a significant project can sometimes take just long enough that your flow gets interrupted, especially if you’re working on large monorepos or projects with a deep dependency graph.
But Rust offers a lesser-known superpower; incremental compilation, and when used effectively, it can shave a significant amount of time off your builds. For some projects, compile times can drop by 50% or more, depending on the code structure and patterns you’re using. In this article, I’ll dive deep into how Rust’s incremental compilation works, show you some tips to optimize it, and explain how you can monitor and tweak your build process for even better performance.
What is Incremental Compilation?
At its core, incremental compilation is about reusing previously compiled work when only small changes are made to the code. Instead of recompiling the entire project from scratch every time, the compiler reuses artifacts (compiled code) from earlier builds, recompiling only what’s necessary.
Rust’s incremental compilation kicks in automatically in debug builds (when optimizations are disabled) and allows you to get faster iteration cycles. The key feature here is how Rust tracks the dependencies between your functions, modules, and crates, allowing it to avoid recompiling parts of the program that haven’t changed.
This is where Rust’s dependency graph comes into play. The compiler builds a graph of your code and the relationships between its components, so when you change one part of the code, only the affected nodes in that graph are recompiled. Sounds good, right?
But there’s more to it — especially when it comes to optimizing incremental compilation.
How Does It Actually Work?
To understand incremental compilation, it helps to know how Rust compiles your code. The…
