Android Emulator Trace

Android Emulator Trace

Use this skill when working with tests/android_emulator_trace.sh, Android UI captures, Android debug Vulkan layers, or emulator trace failures.

Core Rule

Use desktop tools from build/, but push an Android-built Vulkan layer from build_android_<ABI>/.

Do not push build/libVkLayer_lavatube.so to Android. It is a desktop Linux shared object and will fail in logcat with a missing libstdc++.so.6 or another host-library dependency.

Typical x86_64 Emulator Flow

1. Build desktop tools if needed: make -C build -j6
2. Build the Android emulator layer: make -C build_android_x86_64 -j6
3. Start the emulator: tests/emulator_setup.sh
4. Run the trace: tests/android_emulator_trace.sh build_android_x86_64/libVkLayer_lavatube.so build/lava-replay VkLayer_lavatube.json
5. Stop the emulator when done: tests/emulator_cleanup.sh

Checks Before Running

• adb devices should list one emulator.
• adb -e shell getprop ro.product.cpu.abi should match the layer:
  • x86_64 -> build_android_x86_64/libVkLayer_lavatube.so
  • arm64-v8a -> build_android_arm64-v8a/libVkLayer_lavatube.so
• file <layer> should say SYSV, not GNU/Linux.

Trace Verification

After a successful script run, inspect the trace you captured from the repo root (here assuming that the trace is named calendar.api):

build/packtool print metadata.json calendar.api | rg "VK_ANDROID_frame_boundary|VK_EXT_frame_boundary"
build/lava-print calendar.api | rg "vkFrameBoundaryANDROID|vkCreateDevice"

Common Failures

• adb -e wait-for-device hangs: no emulator is running. Run tests/emulator_setup.sh first.
• dlopen failed: library "libstdc++.so.6" not found: a desktop build/libVkLayer_lavatube.so was pushed; rebuild/use build_android_<ABI>/libVkLayer_lavatube.so.
• Trace path missing after launch: check logcat for VkLayer_lavatube, vulkan, dlopen, and lavatube.