[Reportbug-maint] how to reuse a saved file

[Faheem Mitha]

At the bottom of http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=328531 
the changelog for reportbug 3.40 is given.

* reportbug
      - explained how to reuse a saved file (generated by not submitting a bug
        report); (Closes: #328531)

Could someone point me to how one is supposed to do this? I could not 
figure it out. My use case is

1) Cannot send email on machine 1, but want to submit a bug report for 
that machine. So, I write a report on that machine, export the file with 
-o.

2) Copy file to machine 2, then want to try and submit from there.

Please copy me on any reply. I'm not subscribed, Thanks.

                                         Regards, Faheem