swiftpm-linux-cross

This repo provides easy scripts for setting up a toolchain that allows you to cross compile Linux binaries from a macOS machine using Swift Package Manager. This can be useful for building your release binaries on your host machine instead of in a potentially slower VM or docker container.

Replaced by swift-sdk-generator

This repo might still be a useful example if you need to manage this yourself, but moving forward you should use the new swift-sdk-generator project instead.

Usage

$ ./setup-swiftpm-toolchain
Done! To use run:

swift build --destination /Users/ksmiley/dev/swiftpm-linux-cross/toolchain-focal-x86_64-5.6.2/destination.json

Or for static stdlib builds run:

swift build --static-swift-stdlib --destination /Users/ksmiley/dev/swiftpm-linux-cross/toolchain-focal-x86_64-5.6.2/destination_static.json

See the help to customize the OS, architecture, Swift version, or provide your own system package dependencies.

$ ./setup-swiftpm-toolchain --help
usage: setup-swiftpm-toolchain [-h] [--ubuntu-release {bionic,focal}] [--arch {x86_64,arm64}] [--swift-version SWIFT_VERSION] [packages ...]

positional arguments:
  packages              Extra OS packages your build requires

options:
  -h, --help            show this help message and exit
  --ubuntu-release {bionic,focal}
                        The target Ubuntu release you will run on
  --arch {x86_64,arm64}
                        The target architecture to build for
  --swift-version SWIFT_VERSION
                        The version of Swift you're building with and for

Currently this only supports targeting Ubuntu, but it should be extended to support more operating systems.

Installation

With homebrew

brew install keith/formulae/swiftpm-linux-cross

Manually

1. Clone this repo
2. Run any setup-swiftpm-toolchains inside the repo

Matching Swift Versions

To use this your local version of Swift much match the version of Swift the toolchain was created for. This might mean that you have to download a Swift toolchain instead of using the one bundled with Xcode. If this is required you will see an error when building like:

<unknown>:0: error: compiled module was created by a different version of the compiler; rebuild 'Swift' and try again

Once you install the matching toolchain version you can then build using the TOOLCHAINS environment variable like this:

TOOLCHAINS=org.swift.562202206021a swift build --destination /Users/ksmiley/dev/swiftpm-linux-cross/toolchain-focal-x86_64-5.6.2/destination.json

You can fetch the identifier used here from the Info.plist bundled with the toolchain:

/usr/libexec/PlistBuddy -c "print :CFBundleIdentifier" /Library/Developer/Toolchains/swift-latest.xctoolchain/Info.plist

This path varies either in /Library/Developer/Toolchains or ~/Library/Developer/Toolchains depending on how you install it.

References

• This script is outdated but is a useful reference