Comment 2 for bug 499757

John Meinle wrote:

There is currently an open debate for what SilentUIFactory should do
when it is requested to 'make_output_stream'. It will either:
1) Open a connection to stdout
2) Silently discard the data put into the stream

Mostly likely it will be (1), and we just need to update the code to do so.

I think the issue you are running into is that you are calling 'run_bzr'
without going through the test suite helpers that set up the output
files, etc. As such, you have the default UIFactory set up (Silent).
This doesn't happen in the real-world or via TestCase.run_bzr, so we
didn't catch it before now.

I believe mwhudson also commented on this being an issue with some of
his tests failing.

Summary:
 We need to make SilentUIFactory.make_output_stream do the same thing as
 TextUIFactory.make_output_stream.