bazel.rb

require "rake/task"

module Bazel
  class BazelTask < Rake::Task
    def needed?
      true
    end

    def invoke(*args)
      puts "Invoked!"
    end
  end
end

module Rake::DSL
  def bazel(*args, &block)
    Bazel::BazelTask.define_task(*args, &block)
  end
end

This fails when using the following in a Rakefile and ./go

desc "Build core"
bazel "//java/client/src/org/openqa/selenium:core"

with the message: Don't know how to build task '//java/client/org/openqa/selenium:core'.

On the command line with rake 12, the same code is just fine.