Server logging errors are hard to debug

I suddenly began getting warnings on 'bzr push' but not 'bzr pull' that said:

No handlers could be found for logger "bzr"

Googling indicated it was a permission problem on ~/.bzr.log, but looking at
this file on the clients revealed no problem. All were owned by me and had
the proper permission bits.

After extensive pdb tracing, and with the help of JAM, I found out that the
problem was the permission of ~/.bzr.log on the server. This warning was
being generated on the bzr+ssh server and propagated through to the client.
So while it looked like a client problem, it was really a server problem.
Fixing the ownership on the server made it go away.

The bug here then is that server warnings are not indicated as such in the
client. I think the diagnosis would have come much faster if it was clear
that the warning was happening on the server and not the client.

JAM also indicates this problem:

<jam> #1 we need to fix _open_bzr_log
<jam> to just write to stderr, since we know logging isn't set up yet