// ld runs the linker to create an executable starting at mainpkg.
	ld(b *Builder, root *Action, targetPath, importcfg, mainpkg string) error
	// ldShared runs the linker to create a shared library containing the pkgs built by toplevelactions
	ldShared(b *Builder, root *Action, toplevelactions []*Action, targetPath, importcfg string, allactions []*Action) error

	compiler() string
	linker() string
}