Pre-build tasks wouldn't cut it, IIRC. The issue was that compiling the project required compiling part of it (part a), then generating source based on the results of (a), then building that generated source (which required the presence of the compiled results from (a), then compiling the rest of the project (b).

Unless I'm grossly misremembering, pre-build tasks would only have worked if the project had been broken up into separate projects such that the generation script could run post-(a) or pre-(b).