new feature in valgrind 3.4.0 makes it easy to track _origin_ of "uninitialized values"

[Martin Olsson]

FYI;

Valgrind 3.4.0 introduces a really neat feature for finding the reason behind those
pesky "jump/move depends on unintialized memory" errors.

What this new feature does is that it prints the _origin_ of the undefined value
instead of printing a warning when that value is _used_. Normally there is a huge
gap between the origin and the use and that means that with existing valgrind
versions, these warnings can be quiet hard to track down. The new feature makes
them super actionable instead.

This blog post is well worth reading:
http://blog.mozilla.com/nnethercote/2009/02/27/eliminating-undefined-values-with-valgrind-the-easy-way/


Now, I just wish we actually had the stable 3.4.0 version of valgrind in jaunty
(seems we got 3.3.1 right now).