rbx compile -A -e "...

sasha:rubinius brian$ rbx compile -A -e "
class Foo
  include Module.new {
    def this_works
    end
  }

  include Module.new do
    def this_doesnt_work
    end
  end
end

foo = Foo.new
foo.this_works
foo.this_doesnt_work
"
Script
  @file: "(snippet)"
  @pre_exe: []
  @name: :__script__
  @body: \
    Block
      @array: [
        Class [0]
          @line: 2
          @name: \
            ClassName
              @name: :Foo
              @line: 2
              @superclass: \
                NilLiteral
                  @line: 2
          @superclass: \
            NilLiteral
              @line: 2
          @body: \
            ClassScope
              @name: :Foo
              @line: 2
              @body: \
                Block
                  @array: [
                    SendWithArguments [0]
                      @privately: true
                      @name: :include
                      @check_for_local: false
                      @block: nil
                      @line: 6
                      @vcall_style: false
                      @receiver: \
                        Self
                          @line: 6
                      @arguments: \
                        ActualArguments
                          @array: [
                            SendFastNew [0]
                              @privately: false
                              @name: :new
                              @check_for_local: false
                              @line: 3
                              @vcall_style: false
                              @receiver: \
                                ConstantAccess
                                  @name: :Module
                                  @line: 3
                              @block: \
                                Iter19
                                  @line: 3
                                  @locals: nil
                                  @arguments: \
                                    FormalArguments19
                                      @names: []
                                      @optional: []
                                      @post: []
                                      @line: 3
                                      @defaults: nil
                                      @required: []
                                      @splat: nil
                                      @block_arg: nil
                                      @splat_index: nil
                                  @body: \
                                    Define
                                      @name: :this_works
                                      @line: 4
                                      @arguments: \
                                        FormalArguments19
                                          @names: []
                                          @optional: []
                                          @post: []
                                          @line: 4
                                          @defaults: nil
                                          @required: []
                                          @splat: nil
                                          @block_arg: nil
                                          @splat_index: nil
                                      @body: \
                                        Block
                                          @array: [
                                            NilLiteral [0]
                                              @line: 5
                                          ]
                                          @locals: nil
                                          @line: 5
                              @arguments: \
                                ActualArguments
                                  @array: []
                                  @splat: nil
                                  @line: 3
                          ]
                          @splat: nil
                          @line: 6
                    SendWithArguments [1]
                      @privately: true
                      @name: :include
                      @check_for_local: false
                      @line: 8
                      @vcall_style: false
                      @receiver: \
                        Self
                          @line: 8
                      @block: \
                        Iter19
                          @line: 8
                          @locals: nil
                          @arguments: \
                            FormalArguments19
                              @names: []
                              @optional: []
                              @post: []
                              @line: 8
                              @defaults: nil
                              @required: []
                              @splat: nil
                              @block_arg: nil
                              @splat_index: nil
                          @body: \
                            Define
                              @name: :this_doesnt_work
                              @line: 9
                              @arguments: \
                                FormalArguments19
                                  @names: []
                                  @optional: []
                                  @post: []
                                  @line: 9
                                  @defaults: nil
                                  @required: []
                                  @splat: nil
                                  @block_arg: nil
                                  @splat_index: nil
                              @body: \
                                Block
                                  @array: [
                                    NilLiteral [0]
                                      @line: 10
                                  ]
                                  @locals: nil
                                  @line: 10
                      @arguments: \
                        ActualArguments
                          @array: [
                            SendFastNew [0]
                              @privately: false
                              @name: :new
                              @check_for_local: false
                              @block: nil
                              @line: 8
                              @vcall_style: false
                              @receiver: \
                                ConstantAccess
                                  @name: :Module
                                  @line: 8
                              @arguments: \
                                ActualArguments
                                  @array: []
                                  @splat: nil
                                  @line: 8
                          ]
                          @splat: nil
                          @line: 8
                  ]
                  @locals: nil
                  @line: 6
        LocalVariableAssignment [1]
          @name: :foo
          @line: 14
          @variable: nil
          @value: \
            SendFastNew
              @privately: false
              @name: :new
              @check_for_local: false
              @block: nil
              @line: 14
              @vcall_style: false
              @receiver: \
                ConstantAccess
                  @name: :Foo
                  @line: 14
              @arguments: \
                ActualArguments
                  @array: []
                  @splat: nil
                  @line: 14
        Send [2]
          @privately: false
          @name: :this_works
          @check_for_local: false
          @block: nil
          @line: 15
          @vcall_style: false
          @receiver: \
            LocalVariableAccess
              @name: :foo
              @line: 15
              @variable: nil
        Send [3]
          @privately: false
          @name: :this_doesnt_work
          @check_for_local: false
          @block: nil
          @line: 16
          @vcall_style: false
          @receiver: \
            LocalVariableAccess
              @name: :foo
              @line: 16
              @variable: nil
      ]
      @locals: nil
      @line: 2

result

Ruby syntax can be a bit daunting at times. It can be helpful to look
at the tree structure that represents the syntax. Rubinius has a handy
compile command that produces an S-expression, AST tree, or bytecode
from source code. You can see in the AST here that the @block attribute
of the SendWithArguments node for the #include call contains the block
that you may have thought was going to the Module.new call.