[PATCH 4/5] Support backtracing through elfutils (#70746)

[Mark Kettenis]

> Date: Wed, 30 Oct 2013 02:31:19 -0400
> From: "Jasper St. Pierre" <jstpierre at mecheye.net>
> 
> Whoops, I misspoke when I talked about libbacktrace. I meant libunwind all
> throughout, since that's what Xorg uses right now.
> 
> Should we work on making the elfutils backtrace API more like libunwind /
> libbacktrace, and simpler to embed? Right now we have support code in glib
> that forks off gdb and feeds it commands over a stream, which is horribly
> slow and often deadlocks your app; I was planning to replace it with
> libunwind.
> 
> Should we focus on porting libbacktrace / libunwind to elfutils, and have
> one simple API for this?

elfutils is GPL'ed, which is undesirable for Xorg.

libbacktrace is BSD(-ish) licensed, which is much more aligned with
the MIT license used for most of Xorg.