base on “Zero setup” cross compilation and “cross testing” of Rust crates [](https://crates.io/crates/cross) [](https://crates.io/crates/cross) [](https://github.com/cross-rs/cross/actions/workflows/ci.yml?query=branch) [](https://matrix.to/#/#cross-rs:matrix.org) # `cross` > “Zero setup” cross compilation and “cross testing” of Rust crates This project is developed and maintained by the [cross-rs] team. It was previously maintained by the Rust Embedded Working Group Tools team. New contributors are welcome! Please join our [Matrix room] and say hi. <p align="center"> <img alt="`cross test`ing a crate for the aarch64-unknown-linux-gnu target" src="assets/cross-test.png" title="`cross test`ing a crate for the aarch64-unknown-linux-gnu target" > <br> <em>`cross test`ing a crate for the aarch64-unknown-linux-gnu target</em> </p> ## Features - `cross` will provide all the ingredients needed for cross compilation without touching your system installation. - `cross` provides an environment, cross toolchain and cross compiled libraries, that produces the most portable binaries. - “cross testing”, `cross` can test crates for architectures other than i686 and x86_64. - The stable, beta and nightly channels are supported. ## Dependencies See our [Getting Started](./docs/getting-started.md) guide for detailed installation instructions. - [rustup](https://rustup.rs/) - A Linux kernel with [binfmt_misc] support is required for cross testing. One of these container engines is required. If both are installed, `cross` will default to `docker`. - [Docker]. Note that on Linux non-sudo users need to be in the `docker` group or use rootless docker. Read the container engine [install guide][docker_install] for the required installation and post-installation steps. Requires version 20.10 (API 1.40) or later. - [Podman]. Requires version 3.4.0 or later. ## Installation ```sh cargo install cross --git https://github.com/cross-rs/cross ``` It's also possible to directly download the pre-compiled [release binaries](https://github.com/cross-rs/cross/releases) or use [cargo-binstall](https://github.com/cargo-bins/cargo-binstall). ## Usage `cross` has the exact same CLI as [Cargo](https://github.com/rust-lang/cargo) but relies on Docker or Podman. For Docker, you'll have to start the daemon before you can use it. ``` # (ONCE PER BOOT, on Linux) # Start the Docker daemon, if it's not already running using systemd # on WSL2 and other systems using SysVinit, use `sudo service docker start`. $ sudo systemctl start docker # MAGIC! This Just Works $ cross build --target aarch64-unknown-linux-gnu # EVEN MORE MAGICAL! This also Just Works $ cross test --target mips64-unknown-linux-gnuabi64 # Obviously, this also Just Works $ cross rustc --target powerpc-unknown-linux-gnu --release -- -C lto ``` Additional documentation can be found on the [wiki](https://github.com/cross-rs/cross/wiki) or the `docs/` subfolder. ## Configuration ### Configuring cross behavior You have four options to configure `cross`. All of these options use the TOML format for configuration and the possible configuration values are documented [here][config_file]. #### Option 1: Configuring `cross` directly in your `Cargo.toml` You can directly set [configuration values][config_file] in your `Cargo.toml` file, under the `[workspace.metadata.cross]` table, i.e. key prefix. An example config snippet would look like this: ```toml,cargo [workspace.metadata.cross.target.aarch64-unknown-linux-gnu] # Install libssl-dev:arm64, see <https://github.com/cross-rs/cross/blob/main/docs/custom_images.md#adding-dependencies-to-existing-images> pre-build = [ "dpkg --add-architecture $CROSS_DEB_ARCH", "apt-get update && apt-get --assume-yes install libssl-dev:$CROSS_DEB_ARCH" ] [workspace.metadata.cross.target.armv7-unknown-linux-gnueabi] image = "my/image:latest" [workspace.metadata.cross.build] env.volumes = ["A_DIRECTORY=/path/to/volume"] ``` #### Option 2: Configuring `cross` via a `Cross.toml` file You can put your [configuration][config_file] inside a `Cross.toml` file in your project root directory. #### Option 3: Using `CROSS_CONFIG` to specify the location of your configuration By setting the `CROSS_CONFIG` environment variable, you can tell `cross` where it should search for the config file. This way you are not limited to a `Cross.toml` file in the project root. #### Option 4: Configuring `cross` through environment variables Besides the TOML-based configuration files, config can be passed through [environment variables][docs_env_vars], too. ### Docker in Docker When running `cross` from inside a container, `cross` needs access to the hosts docker daemon itself. This is normally achieved by mounting the docker daemons socket `/var/run/docker.sock`. For example: ``` $ docker run -v /var/run/docker.sock:/var/run/docker.sock -v .:/project \ -w /project my/development-image:tag cross build --target mips64-unknown-linux-gnuabi64 ``` The image running `cross` requires the rust development tools to be installed. With this setup `cross` must find and mount the correct host paths into the container used for cross compilation. This includes the original project directory as well as the root path of the parent container to give access to the rust build tools. To inform `cross` that it is running inside a container set `CROSS_CONTAINER_IN_CONTAINER=true`. A development or CI container can be created like this: ``` FROM rust:1 # set CROSS_CONTAINER_IN_CONTAINER to inform `cross` that it is executed from within a container ENV CROSS_CONTAINER_IN_CONTAINER=true # install `cross` RUN cargo install cross ... ``` **Limitations**: Finding the mount point for the containers root directory is currently only available for the overlayfs2 storage driver. In order to access the parent containers rust setup, the child container mounts the parents overlayfs. The parent must not be stopped before the child container, as the overlayfs can not be unmounted correctly by Docker if the child container still accesses it. ### Explicitly choose the container engine By default, `cross` tries to use [Docker] or [Podman], in that order. If you want to choose a container engine explicitly, you can set the binary name (or path) using the `CROSS_CONTAINER_ENGINE` environment variable. For example in case you want use [Podman], you can set `CROSS_CONTAINER_ENGINE=podman`. ## Supported targets A target is considered as “supported” if `cross` can cross compile a “non-trivial” (binary) crate, usually Cargo, for that target. Testing support (`cross test`) is more complicated. It relies on [QEMU] emulation, so testing may fail due to QEMU bugs rather than bugs in your crate. That said, a target has a ✓ in `test` column of the table below if it can run the [`compiler-builtins`] test suite. [QEMU]: https://www.qemu.org/ [`compiler-builtins`]: https://github.com/rust-lang-nursery/compiler-builtins Also, testing is very slow. `cross test` runs units tests *sequentially* because QEMU gets upset when you spawn multiple threads. This means that, if one of your unit tests spawns threads, then it's more likely to fail or, worst, never terminate. | Target | libc | GCC | C++ | QEMU | `test` | |----------------------------------------|-------:|-------:|:---:|------:|:------:| | `aarch64-linux-android` [1] | 9.0.8 | 9.0.8 | ✓ | 6.1.0 | ✓ | | `aarch64-unknown-linux-gnu` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `aarch64-unknown-linux-gnu:centos` [7] | 2.17 | 4.8.5 | | 4.2.1 | ✓ | | `aarch64-unknown-linux-musl` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `arm-linux-androideabi` [1] | 9.0.8 | 9.0.8 | ✓ | 6.1.0 | ✓ | | `arm-unknown-linux-gnueabi` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `arm-unknown-linux-gnueabihf` | 2.31 | 8.5.0 | ✓ | 6.1.0 | ✓ | | `arm-unknown-linux-musleabi` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `arm-unknown-linux-musleabihf` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `armv5te-unknown-linux-gnueabi` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `armv5te-unknown-linux-musleabi` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `armv7-linux-androideabi` [1] | 9.0.8 | 9.0.8 | ✓ | 6.1.0 | ✓ | | `armv7-unknown-linux-gnueabi` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `armv7-unknown-linux-gnueabihf` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `armv7-unknown-linux-musleabi` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `armv7-unknown-linux-musleabihf` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `i586-unknown-linux-gnu` | 2.31 | 9.4.0 | ✓ | N/A | ✓ | | `i586-unknown-linux-musl` | 1.2.3 | 9.2.0 | ✓ | N/A | ✓ | | `i686-unknown-freebsd` | 1.5 | 6.4.0 | ✓ | N/A | | | `i686-linux-android` [1] | 9.0.8 | 9.0.8 | ✓ | 6.1.0 | ✓ | | `i686-pc-windows-gnu` | N/A | 9.4 | ✓ | N/A | ✓ | | `i686-unknown-linux-gnu` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `loongarch64-unknown-linux-gnu` | 2.36 | 14.2.0 | ✓ | 8.2.2 | ✓ | | `loongarch64-unknown-linux-musl` | 1.2.5 | 14.2.0 | ✓ | 8.2.2 | ✓ | | `mips-unknown-linux-gnu` | 2.30 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `mips-unknown-linux-musl` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `mips64-unknown-linux-gnuabi64` | 2.30 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `mips64-unknown-linux-muslabi64` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `mips64el-unknown-linux-gnuabi64` | 2.30 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `mips64el-unknown-linux-muslabi64` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `mipsel-unknown-linux-gnu` | 2.30 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `mipsel-unknown-linux-musl` | 1.2.3 | 9.2.0 | ✓ | 6.1.0 | ✓ | | `powerpc-unknown-linux-gnu` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `powerpc64-unknown-linux-gnu` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `powerpc64le-unknown-linux-gnu` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `riscv64gc-unknown-linux-gnu` | 2.35 | 11.4.0 | ✓ | 8.2.2 | ✓ | | `s390x-unknown-linux-gnu` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `sparc64-unknown-linux-gnu` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `sparcv9-sun-solaris` | 1.22.7 | 8.4.0 | ✓ | N/A | | | `thumbv6m-none-eabi` [4] | 3.3.0 | 9.2.1 | | N/A | | | `thumbv7em-none-eabi` [4] | 3.3.0 | 9.2.1 | | N/A | | | `thumbv7em-none-eabihf` [4] | 3.3.0 | 9.2.1 | | N/A | | | `thumbv7m-none-eabi` [4] | 3.3.0 | 9.2.1 | | N/A | | | `thumbv7neon-linux-androideabi` [1] | 9.0.8 | 9.0.8 | ✓ | 6.1.0 | ✓ | | `thumbv7neon-unknown-linux-gnueabihf` | 2.31 | 9.4.0 | ✓ | N/A | ✓ | | `thumbv8m.base-none-eabi` [4] | 3.3.0 | 9.2.1 | | N/A | | | `thumbv8m.main-none-eabi` [4] | 3.3.0 | 9.2.1 | | N/A | | | `thumbv8m.main-none-eabihf` [4] | 3.3.0 | 9.2.1 | | N/A | | | `wasm32-unknown-emscripten` [6] | 3.1.14 | 15.0.0 | ✓ | N/A | ✓ | | `x86_64-linux-android` [1] | 9.0.8 | 9.0.8 | ✓ | 6.1.0 | ✓ | | `x86_64-pc-windows-gnu` | N/A | 9.3 | ✓ | N/A | ✓ | | `x86_64-pc-solaris` | 1.22.7 | 8.4.0 | ✓ | N/A | | | `x86_64-unknown-freebsd` | 1.5 | 6.4.0 | ✓ | N/A | | | `x86_64-unknown-dragonfly` [2] [3] | 6.0.1 | 10.3.0 | ✓ | N/A | | | `x86_64-unknown-illumos` | 1.20.4 | 8.4.0 | ✓ | N/A | | | `x86_64-unknown-linux-gnu` | 2.31 | 9.4.0 | ✓ | 6.1.0 | ✓ | | `x86_64-unknown-linux-gnu:centos` [5] | 2.17 | 4.8.5 | ✓ | 4.2.1 | ✓ | | `x86_64-unknown-linux-musl` | 1.2.3 | 9.2.0 | ✓ | N/A | ✓ | | `x86_64-unknown-netbsd` [3] | 9.2.0 | 9.4.0 | ✓ | N/A | | <!--| `asmjs-unknown-emscripten` [7] | 3.1.14 | 15.0.0 | ✓ | N/A | ✓ |--> [1] libc = bionic; Only works with native tests, that is, tests that do not depends on the Android Runtime. For i686 some tests may fails with the error `assertion failed: signal(libc::SIGPIPE, libc::SIG_IGN) != libc::SIG_ERR`, see [issue #140](https://github.com/cross-rs/cross/issues/140) for more information. [2] No `std` component available. [3] For some \*BSD and Solaris targets, the libc column indicates the OS release version from which libc was extracted. [4] libc = newlib [5] Must change `image = "ghcr.io/cross-rs/x86_64-unknown-linux-gnu:main-centos"` in `Cross.toml` for `[target.x86_64-unknown-linux-gnu]` to use the CentOS7-compatible target. [6] libc = emscripten and GCC = clang [7] Must change `image = "ghcr.io/cross-rs/aarch64-unknown-linux-gnu:main-centos"` in `Cross.toml` for `[target.aarch64-unknown-linux-gnu]` to use the CentOS7-compatible target. <!--[7] libc = emscripten and GCC = clang. The Docker images for these targets are currently not built automatically due to a [compiler bug](https://github.com/rust-lang/rust/issues/98216), you will have to build them yourself for now.--> Additional Dockerfiles for other targets can be found in [cross-toolchains](https://github.com/cross-rs/cross-toolchains). These include MSVC and Apple Darwin targets, which we cannot ship pre-built images of. ## Debugging ### QEMU_STRACE (v0.1.9+) You can set the QEMU_STRACE variable when you use `cross run` to get a backtrace of system calls from “foreign” (non x86_64) binaries. ``` $ cargo new --bin hello && cd $_ $ QEMU_STRACE=1 cross run --target aarch64-unknown-linux-gnu 9 brk(NULL) = 0x0000004000023000 9 uname(0x4000823128) = 0 (..) 9 write(1,0xa06320,14)Hello, world! = 14 9 sigaltstack(0x4000823588,(nil)) = 0 9 munmap(0x0000004000b16000,16384) = 0 9 exit_group(0) ``` ## Minimum Supported Rust Version (MSRV) This crate is guaranteed to compile on stable Rust 1.77.2 and up. It *might* compile with older versions but that may change in any new patch release. Some cross-compilation targets require a later Rust version, and using Xargo requires a nightly Rust toolchain. ## License Licensed under either of - Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) - MIT License ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) at your option. ### Contribution Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions. ## Code of Conduct Contribution to this crate is organized under the terms of the [Rust Code of Conduct][CoC], the maintainer of this crate, the [cross-rs] team, promises to intervene to uphold that code of conduct. [CoC]: CODE_OF_CONDUCT.md [cross-rs]: https://github.com/cross-rs [Docker]: https://www.docker.com [Podman]: https://podman.io [Matrix room]: https://matrix.to/#/#cross-rs:matrix.org [docker_install]: https://github.com/cross-rs/cross/wiki/Getting-Started#installing-a-container-engine [binfmt_misc]: https://www.kernel.org/doc/html/latest/admin-guide/binfmt-misc.html [config_file]: ./docs/config_file.md [docs_env_vars]: ./docs/environment_variables.md ", Assign "at most 3 tags" to the expected json: {"id":"3344","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"