matrix

type Runner struct {
	// The number of single architecture-version runners that are active at any time.
	Parallelism int
	// List of Go versions to run commands on.
	// These should all be non-beta/RC versions.
	Versions []goversion.GoVersion
	// List of Go architectures (values for GOARCH) to run commands on.
	Architectures []string
	// The root directory that the matrix runner should use to install the Go toolchain versions.
	InstallDirectory string
	// Constructs the command to run for the single architecture-version runner.
	// The implementation should use `exec.CommandContext` and pass in the supplied context
	// to ensure that the command is cancelled if the runner exits early.
	// The GOARCH environment variable is automatically injected with the appropriate value.
	// Additionally, the value of `Path` is ignored
	// and replaced with the path to the installed Go binary.
	// Finally, due to a quirk with how the toolchain install path is resolved,
	// the HOME environment variable is replaced with a synthetic value.
	//
	// To skip a version-architecture pair, return `nil` for this function.
	GetCommand func(ctx context.Context, version goversion.GoVersion, arch string, goExe string) *exec.Cmd
}