How to replicate a previous build

For the same source code, you should trust Quartus to produce exactly the same fitting.

However, variation of build may occur due to either fitter random seed value change or timestamp change(which in effect is an invisible change of source code). This is the case with a device working close to its maximum performance in terms of speed/resource.

For example, Altera states that seed value may change timing performance by 10% whatever that means. The same applies to timestamp or any other trivial change. It is clealy a limitation on the fitter technology - may God help them.