[tor-relays] BWAUTH weightings too volatile. . ."twitchy"

[starlight.2015q2 at binnacle.cx]

>Mon Jun 8 05:25:55 UTC 2015
>> UBSAN seems expensive and doesn't seem
>> it would run other than test, but
>> I didn't work on it long and am not
>> 100% certain.  Was trying ASAN extra
>> stack checking at the time, which may
>> have been the culprit.
>
>As I said in my previous email, if you're
>running releases before 0.2.6.6 (2015),
>Tor won't run under UBSAN due to issues
>that have been fixed in subsequent
>releases.

Had a need to run ASAN+UBSAN and
it works perfectly fine for me with
version 0.2.4.27.

Required a minor patch to convert
a single common variable 'incoming_queue'
to extern.

Performance hit was not as bad as I
thought from the earlier try, but bad
enough that I limited the instrumented
modules to only what's necessary.