sccache

Shared compilation cache for C/C++ and Rust

TLDR

Start server

$ sccache --start-server

Show statistics

$ sccache --show-stats

Stop server

$ sccache --stop-server

Zero statistics

$ sccache --zero-stats

Use with cargo

$ RUSTC_WRAPPER=sccache cargo build

Use with cmake

$ cmake -DCMAKE_C_COMPILER_LAUNCHER=sccache -DCMAKE_CXX_COMPILER_LAUNCHER=sccache [..]

Show advanced statistics including cache location

$ sccache --show-adv-stats

Show statistics in JSON format

$ sccache --show-stats --stats-format json

SYNOPSIS

sccache [--start-server] [--stop-server] [--show-stats] [options]

sccache is a compiler cache supporting C, C++, Rust, and other languages. It caches compilation results to speed up rebuilds.The server runs as a daemon, caching compilation outputs. Subsequent compilations with the same inputs return cached results instantly.Local caching stores results on disk. Cloud backends (S3, GCS, Redis, Azure) enable shared caching across machines and CI.Rust integration through RUSTC_WRAPPER caches rustc invocations. The cargo build system automatically uses the wrapper.C/C++ integration uses compiler launchers or wrapper scripts. CMake's launcher variables provide clean integration.Distributed compilation schedules work across multiple machines. This scales builds beyond single-machine parallelism.

PARAMETERS

--start-server

Start the server daemon.

--stop-server

Stop the server.

--show-stats

Show cache statistics.

--zero-stats

Reset statistics.

--show-adv-stats

Show advanced statistics.

--dist-auth TOKEN

Authenticate to dist server.

--dist-status

Show distributed status.

--stats-format FMT

Set output format for statistics (text or json).

CONFIGURATION

SCCACHE_DIR

Local cache directory path (default: ~/.cache/sccache on Linux, ~/Library/Caches/sccache on macOS).

SCCACHE_CACHE_SIZE

Maximum local cache size (e.g., "10G").

SCCACHE_REDIS

Redis server URL for shared caching across machines.

SCCACHE_BUCKET

S3 bucket name for AWS-based shared caching.

SCCACHE_GCS_BUCKET

Google Cloud Storage bucket for GCS-based shared caching.

SCCACHE_MEMCACHED

Memcached server URL for shared caching (e.g., "tcp://hostname:port").

SCCACHE_ERROR_LOG

Path to redirect server error log output.

SCCACHE_LOG

Logging level for the server (e.g., "debug", "trace").

SCCACHE_RECACHE

When set, overwrite existing cache entries.

RUSTC_WRAPPER

Set to "sccache" to enable caching for Rust builds via cargo.

INSTALL

sudo apt install sccache

sudo dnf install sccache

sudo pacman -S sccache

sudo apk add sccache

sudo zypper install sccache

brew install sccache

nix profile install nixpkgs#sccache

CAVEATS

Non-deterministic builds reduce hit rates. Some compiler options prevent caching. Cloud storage has latency. Server must be running.

HISTORY

sccache was developed by Mozilla starting around 2016 for Firefox builds. It provides an alternative to ccache with cloud storage and Rust support.