Re: Observation on Hadrian's relative performance re current buildsystem

On 17 Nov 2017, at 18:46, Ben Gamari wrote:

Simon Peyton Jones via ghc-devs writes:

...

Urk! I expected Hadrian to be faster because it has more accurate dependencies.

While this is just speculation, this might actually be one of the reasons why the no-op case is slower: in make's case the dependency graph is mostly static whereas in Hadrian the build system needs to discover dependencies dynamically.

Either way, thanks for this characterization, Herbert!

But surely the timing for a full build from scratch is not the most important thing to compare? In my work environment, full builds are extremely rare; the common case is an incremental build after pulling changes from upstream. Is this something you can measure? Regards, Malcolm