how long is a while?
can those automatic rebuilds be delayed by a few hours? since there might be a few checkins happening in a row, and then there is no point to start the rebuild in the middle only to need another one an hour later.
i noticed several times that there are 2 or 3 rebuilds coming in a row. i assumed they were all manually triggered, but if that is not the case then i suspect that in most of those cases only the last rebuild was really useful, wasting lots of cpu cycles in particular on the slower machines which get held up with the first rebuild while the last one would already be available for building.
ideally rebuilds should happen when the code is somewhat stabilized. based on checin frequency that would be when there is no checkins for a while, instead of right when checkins happen...
greetings, martin.