我键入coffee来输入REPL，然后键入a=5，则将引发错误并退出REPL。我已经为此搜索了，但一无所获。我是咖啡ans js的新手，感谢您的帮助。
user@HP-2-1:~$ coffee
coffee> (node:10793) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.
Expression assignment to _ now disabled.
undefined
coffee> a = 5
5
coffee> readline.js:1032
throw err;
^
TypeError [ERR_INVALID_CALLBACK]: Callback must be a function
at maybeCallback (fs.js:129:9)
at Object.write (fs.js:536:14)
at REPLServer.<anonymous> (/usr/lib/coffee-script/lib/coffee-script/repl.js:142:12)
at REPLServer.emit (events.js:194:15)
at REPLServer.EventEmitter.emit (domain.js:441:20)
at REPLServer.Interface._onLine (readline.js:290:10)
at REPLServer.Interface._line (readline.js:638:8)
at REPLServer.Interface._ttyWrite (readline.js:919:14)
at REPLServer.self._ttyWrite (repl.js:712:7)
at ReadStream.onkeypress (readline.js:168:10)
at ReadStream.emit (events.js:194:15)
at ReadStream.EventEmitter.emit (domain.js:441:20)
at emitKeys (internal/readline.js:424:14)
at emitKeys.next (<anonymous>:null:null)
at ReadStream.onData (readline.js:1022:36)
at ReadStream.emit (events.js:189:13)
at ReadStream.EventEmitter.emit (domain.js:441:20)
at addChunk (_stream_readable.js:284:12)
at readableAddChunk (_stream_readable.js:265:11)
at ReadStream.Readable.push (_stream_readable.js:220:10)
at TTY.onStreamRead [as onread] (internal/stream_base_commons.js:94:17)
我正在使用Ubuntu 16.04，nodejs版本是v10.15.2，CoffeeScript版本是1.9.3。