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mozilla/sccache

7,268RustAudience · ops devopsComplexity · 3/5Setup · moderate

TLDR

A shared compilation cache tool from Mozilla that stores build results in the cloud so your whole team and CI servers skip recompiling unchanged files, supporting C, C++, Rust, and GPU compilers.

Mindmap

mindmap
  root((sccache))
    What it does
      Compiler caching
      Shared team cache
      CI speedup
    Cache backends
      Amazon S3
      Google Cloud Storage
      Azure Blob Storage
      Redis
    Supported compilers
      C and C++
      Rust
      GPU compilers
    Features
      Distributed mode
      Encrypted transport
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Things people build with this

USE CASE 1

Share a compiled artifact cache across your dev team in S3 so each source file is only compiled once, no matter who triggers the build.

USE CASE 2

Speed up Rust CI builds by storing cached results in Google Cloud Storage or Azure Blob Storage.

USE CASE 3

Distribute C/C++ compilation jobs across multiple machines on a local network to cut build times dramatically.

USE CASE 4

Drop sccache into an existing Rust or C++ project with a single environment variable change and immediately start caching builds.

Tech stack

Rust

Getting it running

Difficulty · moderate Time to first run · 30min

Requires configuring a cloud storage bucket and credentials for team-shared caching, local-only mode is simpler but limits benefit.

In plain English

Sccache is a tool from Mozilla that speeds up software compilation by remembering the results of previous builds. When a developer compiles a program, each source file gets translated into machine code by a compiler. If the source file has not changed since the last build, there is no reason to redo that translation. Sccache sits in front of the compiler and checks a cache before doing any work: if it has seen that exact file with those exact settings before, it serves the cached result instead of calling the compiler. What makes sccache unusual compared to older tools of this type is that the cache can live in the cloud, not just on the developer's own machine. It supports storing cached build results in Amazon S3, Google Cloud Storage, Azure Blob Storage, Redis, and several other backends. This means that an entire team working on the same codebase can share a single cache, so the first person to build a given file effectively does the work for everyone else. Subsequent builds on any team member's machine, or on a continuous integration server, skip the compilation entirely. It supports a wide range of compilers, including the common C and C++ compilers on all major platforms, Rust, and GPU-specific compilers from NVIDIA and AMD. Using it requires minimal setup: you prefix your compile command with sccache, or set a single configuration variable to use it automatically with Rust's build tool. Sccache also includes an optional distributed compilation mode, where build work can be spread across multiple machines on a network. This mode includes authentication and encrypted transport, which older distributed compilation tools typically lack. The tool is available through most major package managers on macOS, Windows, and Linux, and as prebuilt binaries on the releases page.

Copy-paste prompts

Prompt 1
How do I configure sccache to use an S3 bucket as the shared cache backend for my team's C++ project, including the required environment variables?
Prompt 2
Show me how to set up sccache as the Rust compiler wrapper in a GitHub Actions workflow so CI builds benefit from a shared cache.
Prompt 3
What do I need to configure to enable sccache's distributed compilation mode across multiple build machines on my local network?
Prompt 4
How do I check sccache statistics after a build to see the cache hit rate and understand how much time it saved?
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