为什么未捕获的异常会被记录到Sentry两次？

Question

我在测试我的Flask应用程序中的异常是如何被记录到Sentry上的时，发现同一个异常总是被记录两次，而且堆栈跟踪（stack trace）稍微有点不同。为什么会这样？我该怎么做才能防止这种情况发生呢？

第一次记录的堆栈跟踪如下：

  File "raven/middleware.py", line 35, in __call__
    iterable = self.application(environ, start_response)
  File "flask/app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "flask/app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "app/api_1_0/security/decorators.py", line 52, in decorated
    self._process(permission)
  File "app/api_1_0/security/decorators.py", line 27, in _process
    raise FooException('foo exception in _process')

第二次记录的堆栈跟踪如下：

  File "flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "app/api_1_0/security/decorators.py", line 52, in decorated
    self._process(permission)
  File "app/api_1_0/security/decorators.py", line 27, in _process
    raise FooException('foo exception in _process')

Answer 1

把flask的调试模式设置为关闭

例如：

app.run(debug=True)
to 
app.run(debug=False)

在github上相关的问题： https://github.com/getsentry/raven-python/issues/412