Files
mantra-kmp/composeApp/build.gradle.kts
Kgothatso Ngako eee8fa0fd8 build: package the android secp256k1 natives, with ChillDKG in them
The android app had no android secp256k1 natives at all, and had not had any for
as long as lightning-kmp-core has been a dependency. `dependencyInsight` on
debugRuntimeClasspath resolved every secp256k1 coordinate to
`:secp256k1-kmp:jni:jvm:{darwin,linux,mingw}` -- desktop .so/.dylib/.dll files,
loaded by extracting them from a jar, which cannot work on a device.

The cause is a chain of individually reasonable decisions. lightning-kmp-core
publishes no android variant, so an android consumer resolves it to the jvm one;
the jvm variant asks for `secp256k1-kmp-jni-jvm`; and nothing anywhere asks for
`secp256k1-kmp-jni-android`. lightning-kmp-app names it only in androidDeviceTest,
so consumers of the published library do not get it. It has to be named here.

Naming it alone would not have been enough. bitcoin-kmp's settings.gradle.kts
substituted five of secp256k1-kmp's coordinates to the fork's projects but not
-jni-android, so it would have resolved from Maven Central to stock 0.24.0 --
built from upstream libsecp256k1, with no ChillDKG module. Because the kotlin API
comes from the substituted root project, that combination type-checks and links
and then fails with UnsatisfiedLinkError at the first native call. The rule is
added in the submodule commits this carries.

Submodule commits carried here:

  lightning-kmp-app  ce1ed01 -> 6434282  build: carry the jni-android substitution
                                         down from bitcoin-kmp
    experimental/lightning-kmp  77be7b78 -> 5103b79e
      experimental/bitcoin-kmp  196a479 -> 65c4aab  build: substitute
                                         secp256k1-kmp-jni-android to the
                                         included build too

Verified through the artifact rather than the graph: composeApp-debug.apk now
carries lib/{arm64-v8a,armeabi-v7a,x86,x86_64}/libsecp256k1-jni.so, and `nm -D` on
the arm64 one exports all twelve Java_..._chilldkg_... JNI entry points --
hostpubkey_gen, params_hash, participant_step1/step2/finalize,
coordinator_step1/finalize, and the recover and investigate calls.

The three builds in the chain sit on `build/substitute-jni-android` branches
(lightning-kmp-app on `build/agp-9.4.0`, which now carries two commits) and none
are pushed, so a fresh clone cannot resolve these pointers yet.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-04 23:25:23 +02:00

8.3 KiB