X.Org X Server 1.12.4 segfault in jessie: howto report?

[Hugo Vanwoerkom <hvw59601@care2.com>]

Hi,

In Jessie running the Nvidia driver and Virtualbox 4.2.12 I occasionally 
get an X segfault, like this:

http://pastebin.com/Jp6KQytw

Is this reportable as a bug? And what package should it be reported to?

The segfault always occurs as I switch screens with alt+ctl+F<x>.

Hugo