is there documentation focused on build performance, specifically, on how to maximise it? parallelism, caching setup, etc

one specific question i have is, can i build multiple targets in parallel, given that they all share a common base module? ideally it'd compile the base first and then compile all the targets in parallel afterwards

@robert-stuttaford build performance is pretty much optimized by default and there are no settings to make it faster, only to disable threads etc which makes it slower

builds are always isolated and they share nothing. each has its own cache.

compiling multiple builds in parallel is possible but experience has shown that it is in fact pretty much identical in speed in doing them sequentially

that is because the build already uses a maxed out threadpool, so other builds spent most times waiting

ok, interesting, thank you @thheller!

so given that, the most ideal build set up to take advantage of that is one build with several modules, as that way there'll only be a single cache?

depends on what kind of performance you are talking about

it makes no sense to pull stuff into a build that doesn't belong in it

of course

and multiple builds usually is no problem once their cache is hot

since they'll only compile the minimal set afterwards

yeah caching is difficult because we use buildkite which uses multiple agents on multiple hosts, so right now we effectively run clean every time. we're going to look into ways to ensure a stable caching setup

yes, a proper cache is the most important thing for performance

o7 thank you for responding so quick, have an awesome day sir!

Hello. Does shadow-cljs support subpath imports in the context of :esm target? Or am I doing something wrong? https://github.com/dmg46664/problems/tree/main/02_shadow-subpath-imports

I'm trying to configure server addr for RN app with :local-ip option, looks like option from command shadow-cljs watch android --verbose --config-merge '{:local-ip "127.0.0.1"}' isn't picked up but adding it to ~/.shadow-cljs/config.edn does work. Docs mention that --verbose output should display the used IP(s) but I'm not seeing those messages (https://github.com/thheller/shadow-cljs/blob/846446eb49e51daf9c25b6016603afe38b6d4768/src/main/shadow/cljs/devtools/api.clj#L604 https://github.com/thheller/shadow-cljs/blob/846446eb49e51daf9c25b6016603afe38b6d4768/src/main/shadow/cljs/devtools/api.clj#L604)

I'm trying to use "preact/hooks" in a cljs app, but every time I try to use one of the hooks, I get an error like this: Cannot read properties of undefined (reading '__H') it happens in the repl and when running the app. the require looks roughly like this in the app: (:require ["preact/hooks" :refer [useState]]) anyone happen to know why I might be getting that error and/or what I'm missing?

Hi Thomas, thanks for all the support! Regarding externs again – they are all summed up before being fed to Closure, right? Let’s say we have: • simplified externs/app.txt • and externs/app.js They both will be fed to Closure compiler, right? Or are these mutually exclusive?

correct, they are all added