The "Automatic Rebase" feature can be useful when many developers are working on many different branches and occasionally such a branch is released and the relative code is merged into the trunk. On such event, all the other branches should be "rebased" to integrate the latest production code. The feature can be configured as a pre-build-step to do the rebase automatically on build.
The default behaviour of the current version is to revert the changes on the local workspace, thus ignoring the new code in the trunk, in case of a conflicted merge, and let the build go on.
In some workflows, this can cause the feature branch version to be deployed on acceptance environment without including the latest upstream features.
It will be very useful if the pre-build-step could optionally trigger a failure of the build, this way the developer would have evidence of the need to rebase the code of his branch.
I suggest some way to configure, optionally, the "Rebase with upstream subversion revision" pre-build-step to trigger the failure of the build, using something like a checkbox in the build configuration options.