In the build we're controlling with FBServer, we want to build each change submitted to source control individually, to pinpoint the point of failure when something goes wrong. In addition, we can choose to either do a clean build or an incremental one. Clean builds take about 45 minutes to complete, incremental ones that only touch a few non-essential files can take as few as 5.
Currently, we're doing clean builds randomly, about 30% of the time. However, if something goes wrong or we get a few clean builds in a row, the number of pending changes can get quite large.
It would be nice if one of the FBServer "Special Value" values you can assign to server variables passed in to the script was the current length of the queue for that project. That way, we could do incremental builds only when the queue was over a certain length, and revert to randomly doing clean builds at less busy periods.
Does that sound like a straightforward feature to implement, and does it sound useful to folks in general?