REMINDER: run tests with -race before submitting for review

[Tim Penhey]

Hi All,

As was mentioned in earlier emails, we are trying to get rid of the
races in our code as identified by the Go race detector.

What wasn't clear I guess is "Why now? We have had races for ages."

If we skip over the obvious points of "because it is the right thing to
do", and the "weird intermittent failure could be caused by this", we
have a real reason to drive this to zero now.

There is a bug in Go that the Juju code exercised on the power
architecture. We have someone upstream (Go core dev) that is willing to
work with us to fix the upstream bug IF we can share our code and
machine so they can work on it. However, we need to remove all the race
conditions from the code to be certain that it isn't one of these that
is causing the problems on power.

This is the primary reason why Dave is trying to remove all the races
NOW. However, some commits are being added that are introducing race
conditions. Dave is happy to fix the old ones, but it isn't fair for
other people to keep adding new race conditions.

So... for the tests that you are writing for the code you are changing,
please run these tests with the race flag. This should at least help us
not introduce new races.

Thank you.
Tim