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mozilla
sccache
Rust2016–2026
mozilla / sccache

sccache

Sccache is a ccache-like tool. It is used as a compiler wrapper and avoids compilation when possible. Sccache has the capability to utilize caching in remote storage environments, including various cloud storage options, or alternatively, in local storage.

43Distinct people
50Mentions
1Explicit recommenders
7.9KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Sccache is a ccache-like tool. It is used as a compiler wrapper and avoids compilation when possible. Sccache has the capability to utilize caching in remote storage environments, including various cloud storage options, or alternatively, in local storage.

GitHub

Where it is used

No documented product use was verified in the last source check.

What people are saying

About long compile time, I recommend using sccache. It saved a lot of compile time for me. You can find how to install and use it here: https://github.com/mozilla/sccache

nicklauri used a recommendation phrase. One indexed comment matches. This is a phrase match, not a verdict.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

Mentioned in the same Hacker News threads. That is not proof they are substitutes.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 10:02:42 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year50 dated mentions

Observed mentions: 2016-11-22 14:31:46 UTC to 2026-10-01 16:47:51 UTC.

0369122016-01-01 00:00:00 UTC to 2017-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments20162017-01-01 00:00:00 UTC to 2018-01-01 00:00:00 UTC (exclusive): 1 mentions; 1 submissions, 0 comments2018-01-01 00:00:00 UTC to 2019-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 5 mentions; 1 submissions, 4 comments2020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 7 mentions; 1 submissions, 6 comments20212022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 7 mentions; 1 submissions, 6 comments2023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 11 mentions; 1 submissions, 10 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 5 mentions; 0 submissions, 5 comments2026-01-01 00:00:00 UTC to 2027-01-01 00:00:00 UTC (exclusive): 5 mentions; 2 submissions, 3 comments. Incomplete calendar period.2026*

* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20162016-01-01 00:00:00 UTC2017-01-01 00:00:00 UTC101
20172017-01-01 00:00:00 UTC2018-01-01 00:00:00 UTC110
20182018-01-01 00:00:00 UTC2019-01-01 00:00:00 UTC202
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC514
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC404
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC716
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC716
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC11110
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC202
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC505
2026 (partial)2026-01-01 00:00:00 UTC2027-01-01 00:00:00 UTC523

From the project README

An excerpt from the repository, fetched Nov 13, 2026.

Read the project’s introduction
sccache - Shared Compilation Cache sccache is a ccache-like compiler caching tool. It is used as a compiler wrapper and avoids compilation when possible, storing cached results either on local disk or in one of several cloud storage backends. Multi-level caching with automatic backfill is supported for hierarchical cache architectures (see Multi-Level Cache). sccache includes support for caching the compilation of Assembler, C/C++ code, Rust, as well as NVIDIA's CUDA using nvcc, and clang, AMD's ROCm HIP. sccache also provides icecream-style distributed compilation (automatic packaging of local toolchains) for all supported compilers (including Rust). The distributed compilation system includes several security features that icecream lacks such as authentication, transport layer encryption, and sandboxed compiler execution on build servers. See the distributed quickstart guide for more information. sccache is also available as a GitHub Actions to facilitate the deployment using GitHub Actions cache. Table of Contents (ToC) Installation Usage Build Requirements Build Separating caches between invocations Overwriting the cache Debugging Interaction with GNU make jobserver Known Caveats Storage Options Multi-Level (Hierarchical Caching) Local S3 R2 Redis Memcached Google Cloud Storage Azure GitHub Actions WebDAV (Ccache/Bazel/Gradle compatible) Alibaba OSS Tencent Cloud Object Storage Installation There are prebuilt x86-64 binaries available for Windows, Linux (a portable binary compiled against musl), and macOS on the releases page. Several package managers also include sccache packages, you can install the latest release from source using cargo, or build directly from a source checkout. macOS On macOS sccache can be installed via Homebrew: brew install sccache or via MacPorts: sudo port install sccache Windows On Windows, sccache can be installed via scoop: scoop install sccache or winget: winget install Mozilla.sccache Via cargo If you have a Rust toolchain installed you can install sccache using cargo. Note that this will compile sccache from source which is fairly resource-intensive. For CI purposes you should use prebuilt binary packages. cargo install sccache --locked Or, using cargo-binstall to install a prebuilt binary: cargo binstall sccache With Nix Sccache is available in nixpkgs, so if you don't need the latest version you can use that: buildInputs = [ pkgs.sccache ]; We also provide a flake with an overlay for getting the latest version: { inputs = { nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable"; sccache = { url = "github:mozilla/sccache"; inputs.nixpkgs.follows = "nixpkgs"; }; }; outputs = { self, nixpkgs, sccache, ... }: let system = "x86_64-linux"; pkgs = import nixpkgs { inherit system; overlays = [ sccache.overlays.default ]; }; in { devShells.${system}.default = pkgs.mkShell { buildInputs = [ pkgs.sccache ]; }; }; } Or use it directly from the flake without the overlay: nix run github:mozilla/sccache -- --help nix shell github:mozilla/sccache Usage Running sccache is like running ccache: prefix your compilation commands with it, like so: sccache gcc -o foo.o -c foo.c If you want to use sccache for caching Rust builds you can define build.rustc-wrapper in the cargo configuration file. For example, you can set it globally in $HOME/.cargo/config.toml by adding: [build] rustc-wrapper = "/path/to/sccache" Note that you need to use cargo 1.40 or newer for this to work. Alternatively you can use the environment variable RUSTC_WRAPPER: export RUSTC_WRAPPER=/path/to/sccache cargo build sccache supports gcc, clang, MSVC, rustc, NVCC, NVC++, hipcc, and Wind River's diab compiler. Both gcc and msvc support Response Files, read more about their implementation here. If you don't specify otherwise, sccache will use a local disk cache. sccache works using a client-server model, where the server runs locally on the same machine as the client. The client-server model allows the server to be more efficient by keeping some state in memory. The sccache command will spawn a server process if one is not already running, or you can run sccache --start-server to start the background server process without performing any compilation. By default sccache server will listen on 127.0.0.1:4226, you can specify environment variable SCCACHE_SERVER_PORT to use a different port or SCCACHE_SERVER_UDS to listen on unix domain socket. Abstract unix socket is also supported as long as the path is escaped following the format. For example: % env SCCACHE_SERVER_UDS=$HOME/sccache.sock sccache --start-server # unix socket % env SCCACHE_SERVER_UDS=\\x00sccache.sock sccache --start-server # abstract unix socket You can run sccache --stop-server to terminate the server. It will also terminate after (by default) 10 minutes of inactivity. Running sccache --show-stats will print a summary of cache statistics. Some notes about using sccache with Jenkins are here. To use sccache with cmake, provide the following command line arguments to cmake 3.4 or newer: -DCMAKE_C_COMPILER_LAUNCHER=sccache -DCMAKE_CXX_COMPILER_LAUNCHER=sccache The process for using sccache with MSVC and cmake, depends on which version of cmake you're using. For versions of cmake 3.24 and earlier, to generate PDB files for debugging with MSVC, you can use the /Z7 option. Alternatively, the /Zi option together with /Fd can work if /Fd names a different PDB file name for each object file created. Note that CMake sets /Zi by default, so if you use CMake, you can use /Z7 by adding code like this in your CMakeLists.txt: if(CMAKE_BUILD_TYPE STREQUAL "Debug") string(REPLACE "/Zi" "/Z7" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}") string(REPLACE "/Zi" "/Z7" CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG}") elseif(CMAKE_BUILD_TYPE STREQUAL "Release") string(REPLACE "/Zi" "/Z7" CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}") string(R
Read the full README on GitHub

What Hacker News says

1 sources
It does have a bunch of tests, although probably not enough. I've been meaning to add code coverage stats to its CI, although I've only used kcov for Rust code coverage so far, and that only works on Linux it wouldn't reflect reality very well. I've done a lot of work on test automation at Mozilla over the years so automated testing is pretty important to me. :) I've tried to write unit tests where they made sense, they're generally placed within the relevant source file in the tree, like the cache tests here: https://github.com/mozilla/sccache/blob/6eadccc9d6752747766d... I also wrote some higher-level tests that test the server functionality: https://github.com/mozilla/sccache/blob/master/src/test/test... I rolled my own set of traits and structs to mock process execution for those tests so they would run independent of the compilers in
Read the rest
stalled on the system: https://github.com/mozilla/sccache/blob/master/src/mock_comm... I actually like how that code turned out, I've thought about cleaning it up and publishing it as a standalone crate. Rust doesn't have a real test mocking solution yet, and even if it did this is a special case since the standard library's process execution types don't implement a trait that could be mocked. As development went on I realized I didn't have automated tests that tested the whole program, especially running against real compilers (which is important given that the tool is a compiler wrapper), so I wrote some "system" tests that run the actual binary with an actual compiler and local disk cache and verify that it works as expected: https://github.com/mozilla/sccache/blob/master/src/test/syst...
In Sccache, Mozilla’s distributed compiler cache, now written in Rust

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