In my setup, when the source control fails while checking for modifications, no email is sent and my CCtray just stays green and the CCnet webapp does not indicate any broken build. If the source control keeps failing (e.g. because something (in the ccnet server repository breaks it), then the continuous-integration build is silently broken. That situation is indistinguishable from that in which nothing is being checked in; everything looks green and peachy until I start diving into logs (because I notice that the last CCnet build was the day before yesterday).

The particular failure I'm experiencing this with is from SourceSafe: "Source control operation failed: A writable copy of C:\...\foo.ascx already exists". This appears as a CruiseControlException thrown from ThoughtWorks.CruiseControl.Core.Sourcecontrol.ProcessSourceControl.Execute(ProcessInfo processInfo)