Building

Mutagen's build is slightly unique because it needs to cross-compile agent binaries for remote platforms (with cgo support in the case of macOS) and then generate a bundle of these binaries to ship alongside the Mutagen CLI. As such, using go get or go install to acquire Mutagen will result in an incomplete installation, and users should instead download the release builds from the releases page or install Mutagen via Homebrew.

However, Mutagen can be built locally for testing and development. Mutagen relies on the Go toolchain's module support, so make sure that you have Go module support enabled.

Individual Mutagen executables can be built normally using the Go toolchain, but a script is provided to ensure a normalized build, manage cross-compiled builds and agent bundle creation, and perform code signing on macOS. To see information about the build script, run:

go run scripts/build.go --help

The build script can do four different types of builds: local (with support for the local system only), slim (the default - with support for a selection of common platforms used in testing), release (used for generating complete release artifacts), and release-slim (used for generating complete release artifacts for a selection of common platforms used in testing). macOS is currently the only platform that supports doing release builds, because the macOS binaries require cgo support for filesystem monitoring.

All artifacts from the build are placed in a build directory at the root of the Mutagen source tree. As a convenience, artifacts built for the current platform are placed in the root of the build directory for easy testing, e.g.:

go run scripts/build.go
build/mutagen --help

Protocol Buffers code generation

Mutagen uses Protocol Buffers extensively, and as such needs to generate Go code from .proto files. To avoid the need for developers (and CI systems) to have the Protocol Buffers compiler installed, generated code is checked into the repository. If a .proto file is modified, code can be regenerated by running

go generate ./pkg/...

in the root of the Mutagen source tree.

The go generate commands used by Mutagen rely on Go module support being enabled. You will also need to have the protoc compiler (with support for Protocol Buffers 3) available in your path, but not the Go generator, which will be built as part of the go generate command.