My app signaled an Error, which was handled at a higher level to
present a nice message to the user.

However, I want to see the stack that led to it.  I have the Error
instance that was signaled and I see I have ToolSet class>>#debug:, et
al.

But by the time it unwinds and I get hold of Error, its
signalerContext is gone, so I can't get anything useful from the
debugger.

As this script shows, in the handler I still have access to the
signalerContext, but once I unwind back out, its gone.

So is there a way to debug an old error?

     | errorToDebug |
     errorToDebug := [Error signal]
          on: Error
          do:
               [ : err | errorToDebug := err.
               self assert: err signalerContext sender notNil.
               err ].
     self assert: errorToDebug signalerContext sender notNil

Thanks.