Don't understand macros compile error

[veksha]

    import macros
    macro gen() =
      newProc(name=newIdentNode("test"),
                    params=[
                      newIdentNode("int"),
                      nnkIdentDefs.newTree(
                        newIdentNode("x"),
                        newIdentNode("int"),
                        newNimNode(nnkEmpty)
                        )
                      ],
                    body=nnkStmtList.newTree(
                          nnkInfix.newTree(
                            newIdentNode("+"),
                            newIdentNode("x"),
                            newLit(2)
                            )
                          )
                        )
    gen
    
    
    Run
    
    
    echo test 44
    
    
    Run