There are two classes of builder: Supported and Unsupported. The basic policy is that if a supported builder goes red then we fix it right away.

1. It could be we just committed a patch that breaks Tahoe in a way that makes a test fail on that builder. In this case we either:
   1. Revert that patch.
   2. Commit a new patch that fixes the previous patch (careful ...)

2. It could be that the new patch doesn't break Tahoe, but that the unit tests incorrectly think it does, in which case we either:
   1. Commit a new patch that fixes the unit tests.
   2. Commit a new patch that marks that test as "skip" on that builder.

3. It could be that something in the configuration of the build machine has changed which breaks Tahoe and/or Tahoe's unit tests. In that case we either:
   1. Commit a new patch which makes Tahoe work on that new configuration.
   2. Get the administrator of that build machine to change the configuration so that Tahoe works again.

In any of these cases, we might be unable to resolve the redness in a timely manner. In that case we demote that builder from the Supported Builders page to the Unsupported Builders page, as linked from the Buildbot button at the top of every page on this site.