Incremental building - Githubissues

tweag / nix-hour

Questions for the weekly Nix Hour

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Incremental building #66

Open infinisil opened 4 months ago

infinisil commented 4 months ago

How can Nix do incremental builds?

Could include:

Derivation-based incrementality
The new pkgs.checkpointBuildTools
Ccache
Experimental Dynamic derivations
edolstra's nix-ccache

infinisil commented 4 months ago

We decided to focus on this topic for this weeks Nix Hour, this Tuesday at 18:00 CET! If anybody has any extra questions about this topic, either:

Ask them in this issue in advance with a comment
Join the livestream and use the chat to ask questions live

tcurdt commented 4 months ago

Questions:

Even with 100% of the inputs cached it seems like the evaluation of a derivation can take quite some time - why?
Understanding the build output in more detail would be nice. [1/2/37 built, 14/42/66 copied (86.9/251.3 MiB), 24.1/59.6 MiB DL] fetching zstd-1.5.5-man from https://cache.nixos.org Especially the 1/2/37 and 14/42/66 in the above case.
What's the best way to minimize builds from source on deployments (is cachix the only solution?)

infinisil commented 4 months ago

@tcurdt We touched upon your questions at 48:26 :)

Since we didn't get through everything, we'll focus on this topic again for this weeks Nix Hour, this Tuesday at 18:00 CET! If anybody has any extra questions about this topic, either:

Ask them in this issue in advance with a comment
Join the livestream and use the chat to ask questions live

tcurdt commented 4 months ago

@tcurdt We touched upon your questions at 48:26 :)

Sorry, I didn't make the live steam. But that was super helpful. Thanks!

Still so much more to learn 🙄