R8 optimizedResourceShrinking crash

[JJSarrasin]

By enabling the Gradle config android.r8.optimizedResourceShrinking=true (see https://android-developers.googleblog.com/2025/09/improve-app-performance-with-optimized-resource-shrinking.html)

A crash occurs in release (minify) build when using: Libs.Builder().withContext(context).build()

Note that this Gradle config will be enabled by default in AGP 9.0.0 (very soon).

Here is the crash and the stacktrace:

Fatal Exception: java.lang.IllegalStateException
Please provide the required library data via the available APIs. Depending on the platform this can be done for example via `Libs.Builder().withJson()`. For Android there exists an `Libs.Builder().withContext(context).build()`, automatically loading the `aboutlibraries.json` file from the `raw` resources folder. When using compose or other parent modules, please check their corresponding APIs.

com.mikepenz.aboutlibraries.Libs$Builder.build (Libs.kt:44)
my.package.SettingsLicensesScreenKt$SettingsLicensesScreen$libraries$2$1$1.invokeSuspend (SettingsLicensesScreen.kt:30)
kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith (ContinuationImpl.kt:33)
kotlinx.coroutines.DispatchedTask.run (DispatchedTask.kt:100)
kotlinx.coroutines.internal.LimitedDispatcher$Worker.run (LimitedDispatcher.kt:124)
kotlinx.coroutines.scheduling.TaskImpl.run (Tasks.kt:89)
kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely (CoroutineScheduler.kt:586)
kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask (CoroutineScheduler.kt:820)
kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker (CoroutineScheduler.kt:717)
kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run (CoroutineScheduler.kt:704)

[mikepenz]

If the file is not named the exact way it's named by default, you will have to provide it yourself, as the auto discovery can't work in that case.

[JJSarrasin]

Is there some proguard rules we can define to continue using the default builder on Android ?

[mikepenz]

I am not aware of such, as this is resource shrinking related and not obfuscation (proguard) related.

[JJSarrasin]

So maybe the Libs.Builder().withContext(context).build() should be removed in a further release if it won't be compatible with the default AGP 9.0.0 configuration.

[mikepenz]

https://developer.android.com/topic/performance/app-optimization/customize-which-resources-to-keep

[svenjacobs]

https://developer.android.com/topic/performance/app-optimization/customize-which-resources-to-keep

I also struggle with this after the upgrade to AGP 9.0. What is the correct syntax of the keep file? The following does not work:

<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:tools="http://schemas.android.com/tools"
    tools:keep="@raw/aboutlibraries.json" />

[mikepenz]

@svenjacobs so you already confirmed the file is generated in the right location (not sure where you upgraded from, but the last major release split android from the general plugin - so you might need to add the extra plugin if you don't have that already)

[svenjacobs]

I use the Android plugin of AboutLibraries. The files are generated into app/build/generated/aboutLibraries/debug/res/raw/aboutlibraries.json and app/build/generated/aboutLibraries/beta/res/raw/aboutlibraries.json. The beta build type has minification/shrinking enabled and since AGP 9.0 crashes on the licenses screen.

I'm not sure if

tools:keep="@raw/aboutlibraries.json"

is correct?

[mikepenz]

Do you see output in:

Gradle also creates a diagnostic file named resources.txt in <module-name>/build/outputs/mapping/release/ (the same folder as ProGuard's output files). The file includes details such as which resources reference other resources and which resources are used or removed.

regarding that file being removed?

I don't know have had too much exposure to that new resource shrinking yet :/ so I don't have an answer :(

[svenjacobs]

Do you see output in

Yes, there's the line

raw:aboutlibraries:2131689472 is not reachable

in resources.txt.

[svenjacobs]

My bad, the file extension in the declaration of the keep file was wrong. This is correct and works:

<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:tools="http://schemas.android.com/tools"
    tools:keep="@raw/aboutlibraries" />

Maybe an information could be added to the documentation of AboutLibraries?

[mikepenz]

Yes, that makes sense. Would you be so kind to open a contribution for this, please?