Using ccache on CURRENT

Hi fellow CURRENT users!

I am trying to follow CURRENT on the desktop system. My typical upgrade path is to update base and then ports/packages. Having monsters like ungoogled-chromium, signal-desktop built upon electron, and libreoffice results in the build times around one week! %)

I have tried to plug ccache in, but it seems not to help much! My understanding is that ccache uses hashes of both the sources AND the compilers to store the results. If I recompile the base system each upgrade, the old hashes are gone! Do I understand it correctly?

Are there any tricks around to still get ccache working? Something like activating reproducible builds in base (and ports)? The actual changes of both system and port compilers are not that often!


Thank you in advance,
Alexey