Speed up Android builds

[roryabraham]

Problem

Android builds typically take 10-30 minutes on my M2 Mac, which is a long time.

Solution

Research ways to speed them up

[roryabraham]

There are a few things I'd like to try:

• Enable gradle build cache
• Enable gradle configuration cache
• Enable gradle parallel task execution
• Enable ccache

[roryabraham]

In order to be methodic and quantitative with these changes, I'll be using ./gradlew build --scan to generate detailed build scan reports.

[roryabraham]

Build scan for a clean ./gradlew assembleDebug (note: next time I should do active arch only, because that's what we do in dev)

https://scans.gradle.com/s/4e4x4kl55d3js

[roryabraham]

Another clean build scan, this time only one arch: https://scans.gradle.com/s/4apezfw7xtotm

Build command was: ./gradlew assembleDebug -PreactNativeArchitectures=arm64-v8a --scan

[roryabraham]

A build scan with only this diff:

diff --git a/android/gradle.properties b/android/gradle.properties
index 87333d20f74..1f60a7d335d 100644
--- a/android/gradle.properties
+++ b/android/gradle.properties
@@ -55,3 +55,6 @@ MYAPP_UPLOAD_KEY_ALIAS=ReactNativeChat-Key-Alias
 disableFrameProcessors=true
 
 android.nonTransitiveRClass=false
+
+org.gradle.parallel=true

https://scans.gradle.com/s/67qe4vuqgytyq

[roryabraham]

Adding the org.gradle.caching=true does not appear to be worth it, because:

• It has no effect on the configuration phase, which consistently takes about 10 minutes while the build phase takes about 1 minute w/ parallel enabled.
• Even a cached build seemed to take about a minute, but populating the cache takes longer

[roryabraham]

Going to try the configuration cache field with:

./gradlew assembleDebug --configuration-cache -PreactNativeArchitectures=arm64-v8a --scan

Edit: 2nd build w/ configuration cache enabled failed 😞

Logs

FAILURE: Build failed with an exception.

* Where:
Settings file '/Users/roryabraham/Expensidev/App/android/settings.gradle' line: 3

* What went wrong:
Configuration cache problems found in this build.

9752 problems were found storing the configuration cache, only the first 4096 were considered, 7 of which seem unique.
- Build file '../node_modules/@expensify/react-native-live-markdown/android/build.gradle': external process started 'node --print require.resolve('react-native/package.json')'
  See https://docs.gradle.org/8.8/userguide/configuration_cache.html#config_cache:requirements:external_processes
- Build file 'app/build.gradle': external process started 'node --print require.resolve('@expo/cli')'
  See https://docs.gradle.org/8.8/userguide/configuration_cache.html#config_cache:requirements:external_processes
- Build file 'app/build.gradle': external process started 'node -e require('expo/scripts/resolveAppEntry') /Users/roryabraham/Expensidev/App android absolute'
  See https://docs.gradle.org/8.8/userguide/configuration_cache.html#config_cache:requirements:external_processes
- Build file 'build.gradle': external process started 'node --print JSON.parse(require('fs').readFileSync(require.resolve('react-native/package.json'), 'utf-8')).version'
  See https://docs.gradle.org/8.8/userguide/configuration_cache.html#config_cache:requirements:external_processes
- Build file 'build.gradle': line 47: external process started 'node --print JSON.parse(require('fs').readFileSync(require.resolve('react-native/package.json'), 'utf-8')).version'
  See https://docs.gradle.org/8.8/userguide/configuration_cache.html#config_cache:requirements:external_processes
- Settings file 'settings.gradle': line 26: external process started 'node --print require.resolve('expo/package.json')'
  See https://docs.gradle.org/8.8/userguide/configuration_cache.html#config_cache:requirements:external_processes
- Settings file 'settings.gradle': line 3: external process started 'npx @react-native-community/cli config'
  See https://docs.gradle.org/8.8/userguide/configuration_cache.html#config_cache:requirements:external_processes

[roryabraham]

This branch enabling ccache for Android builds also does not seem to materially improve the configuration time. Not sure if it's all done correctly though

[roryabraham]

Another simple thing we could try is providing more RAM to the gradle build. Pretty sure it gets only 512MB by default. We could try bumping that to 2048 (or even higher) and see if it helps