[david-allison]

Note

Assisted-by: Claude Opus 5 - original gradle script
Assisted-by: GPT-6-Astra xhigh - reviewed, rewrote & tested it

Purpose / Description

By duplicating the backend library on disk, we allow support for multiple classloaders.

As these libraries are persistent (but hashed) on-disk, we need a utility to inform developers that old versions are taking up space.

Now this is implemented, we then start improving tests to move them away from Robolectric.

Fixes

• Fixes [Bug] Unit Tests: java.lang.UnsatisfiedLinkError: 'byte[][] net.ankiweb.rsdroid.NativeMethods.openBackend(byte[])' when mixing RunWith(AndroidJUnit4::class) #14796
• Fixes flaky screenshot test: Extracted file was not found... /tmp/librsdroid-[hash] #21769
• See feat(class-loader): handle backend requests from multiple classloaders Anki-Android-Backend#713

Approach

• Backend bump
• include feat(class-loader): handle backend requests from multiple classloaders Anki-Android-Backend#713
• Simplify a number of tests which were unable to

How Has This Been Tested?

Performance: we're likely only looking at 5s of difference, this mostly exists to fix various test-related frustrations and flakes.

./gradlew :AnkiDroid:testFullDebugUnitTest --rerun -PbackendTempLibraryWarnBytes=0 --console=plain

> Task :AnkiDroid:testFullDebugUnitTest FAILED
> Task :AnkiDroid:finalizeTestRoborazziFullDebug SKIPPED
Anki backend test libraries are using 244.5 MiB (5 files):
    46.0 MiB  /private/var/folders/ym/nqynp93d4j74dpzw20sq4wq00000gn/T/librsdroid-30a774fd156c9b354bab88ebbb62748eebfbd2a6-1.dylib
    46.0 MiB  /private/var/folders/ym/nqynp93d4j74dpzw20sq4wq00000gn/T/librsdroid-30a774fd156c9b354bab88ebbb62748eebfbd2a6-2.dylib
    46.0 MiB  /private/var/folders/ym/nqynp93d4j74dpzw20sq4wq00000gn/T/librsdroid-30a774fd156c9b354bab88ebbb62748eebfbd2a6.dylib
    60.7 MiB  /private/var/folders/ym/nqynp93d4j74dpzw20sq4wq00000gn/T/librsdroid-be836b4f2ce70bd1d2cf36a27d8da6d1d3b44872.dylib
    46.0 MiB  /private/var/folders/ym/nqynp93d4j74dpzw20sq4wq00000gn/T/librsdroid-f1a104ccb1b574fff5839a70fbb478551c1fc8fc.dylib
rsdroid-testing keeps an original and up to five copies per checksum by default, for reuse across classloaders.
By default these files live outside the project and are not removed by Gradle clean.
To reclaim space, stop tests in all checkouts and IDEs, then delete the listed library files.
Needed libraries will be extracted again on the next test run. Leave .lock files in place.

Learning

I had a longer writeup, but forgot to submit it last night :/

Checklist

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[mikehardy]

Assisted-by: grok-4.7-medium

Thanks — the per-classloader backend copy and the temp-dir warning look right for the mixed Jvm/Robolectric suite.

Replayed four commits onto current main without pushing (PRE_TIP 299f6c8f). Local buildSrc, lint/CQ, full unit, and playRelease emulator on API 36 (emulator-5554 / API36_GAPI_PS16K) passed.

Backend 0.1.72 loads a separate native library file per classloader, Robolectric always runs ensureSetup(), and the Gradle report warns when temp rsdroid copies exceed the configured threshold.

[david-allison]

@ankidroid/reviewers - this is a potentially big one - deep review requested of the gradle change

[mikehardy]

It seems fine on a read, and I don't think it'll get better with age
can always follow on...