exec_result
A structure storing result of repository_ctx.execute() method. It contains the standard output stream content, the standard error stream content and the execution return code.
      return_code
        int exec_result.return_code
    The return code returned after the execution of the program. 256 if an error happened while executing the command.
        
stderr
        string exec_result.stderr
    The content of the standard error output returned by the execution.
        
stdout
        string exec_result.stdout
    The content of the standard output returned by the execution.