tcl和ns2中的错误

Question

我正在使用ns2和TCL语言，我处理一个问题：

ns: _o159 stop: 
    (_o159 cmd line 1)
    invoked from within
"_o159 cmd stop"
    invoked from within
"catch "$self cmd $args" ret"
    invoked from within
"if [catch "$self cmd $args" ret] {
set cls [$self info class]
global errorInfo
set savedInfo $errorInfo
error "error when calling class $cls: $args" $..."
    (procedure "_o159" line 2)
    (SplitObject unknown line 2)
    invoked from within
"_o159 stop"

我该如何解决？