"singleton can't be dumped" error when storing an object in session

[armanx]

Hello everyone,

I'm using Rack::Session::Cookie to store an object (a Sequel model returned by a database call) in the session. However, I'm getting a "singleton can't be dumped" error when trying to do so. What is the reason for this error?

The interesting thing is, I only get the error when the Sequel object is first saved in the database then returned; the error is absent when the record already exists in the database and is returned via select (without saving), yet in both cases the objects/classes are identical.

[armanx]

Is it possible that the object is too large for the 4kb cookie size limit and that's what is causing this error?

[Eric Wong]

armanx <arm...@gmail.com> wrote:
> On Saturday, May 26, 2012 2:39:08 AM UTC-7, armanx wrote:
> > I'm using Rack::Session::Cookie to store an object (a Sequel model
> > returned by a database call) in the session. However, I'm getting a
> > "singleton can't be dumped" error when trying to do so. What is the reason
> > for this error?

(top-posting corrected)

You need to look up the definition of a singleton object.

> > The interesting thing is, I only get the error when the Sequel object is
> > first saved in the database then returned; the error is absent when the
> > record already exists in the database and is returned via select (without
> > saving), yet in both cases the objects/classes are identical.

Not a Sequel expert here, but could it be Sequel is giving you a
different return value than what you expect? Can you share this
piece of code that's giving you trouble?

> Is it possible that the object is too large for the 4kb cookie size limit
> and that's what is causing this error?

No, based on your error, it's not too large.