Startup Failure on iPadOS 26.3 (M4): Hardcoded Flag Conflict and JIT Injection Failure

[Lhy-wed]

Describe the bug

When running on an unjailbroken iPad Air (M4) with iPadOS 26.3, the Amethyst launcher encounters two core issues that prevent the game from running:

JVM Flag Conflict: The launcher forcibly injects the -XX:+MirrorMappedCodeCache flag, which is unrecognized by Java 8, causing the JVM to crash during initialization (see 1.12.2_UniversalJIT.js_log_1.txt). Manually adding -XX:+IgnoreUnrecognizedVMOptions in the JVM settings resolves the crash(see 1.12.2_UniversalJIT.js_log_2), but the screen remains black.

JIT Injection Exception: JIT acquisition fails when using manic.js in StikDebug (v3.0.1)(see 1.12.2_manic.js_log1 and 1.12.2_manic.js_stikdebug_log1_1.png and ...2.png). Even attempting to launch with UniversalJIT26.js (extracted from the Amethyst IPA) does not work.

The log file and images/videos

No response

Steps To Reproduce

1.Use Amethyst v1.0-development on iPadOS 26.3.

2.Attempt to launch version 1.12.2.

3.Scenario A: Launch directly; the JVM exits with the error Unrecognized VM option 'MirrorMappedCodeCache', and StikDebug reports an error.
Scenario B: Launch after adding -XX:+IgnoreUnrecognizedVMOptions; the game stays on a black screen, and StikDebug reports an error.

Expected Behavior

The game should launch and run normally.

Platform

- Device model: iPad Air 8 m4 256GB 11inch
- iOS version: iPad os 26.3
- Amethyst version: Amethyst 1.0-development (main/ba4a002)

Anything else?

1.12.2_manic.js_log1.txt

1.12.2_UniversalJIT.js_log_1.txt

1.12.2_UniversalJIT.js_log_2.txt

1.12.2_UniversalJIT.js_stikdebug_log_2.MP4

[Lhy-wed]

1.12.2_UniversalJIT.js_stikdebug_log_1.mp4

[Xiaolin164]

Known issue:
Minecraft versions that require Java 8 do not launch
iOS 26
requires updated Java 8 port

[Xiaolin164]

Is that the problem?

[Lhy-wed]

Known issue: Minecraft versions that require Java 8 do not launch iOS 26 requires updated Java 8 port

Hi, I want to add some details. On my M4 iPad Air (iOS 26.3), even the latest Minecraft versions fail to launch.
I have enabled JIT using StikDebug, and Amethyst (AAMC) shows JIT turn on in the bottom-left corner. This means the launcher has successfully detected the JIT entitlement.
However, the game still won't start—it just shows a black screen or crashes immediately. I’m not sure if this is a compatibility issue with Amethyst's Java runtime on iOS 26, or if there's a bug with the JIT granted by StikDebug that prevents the Java VM from working correctly.
I'm happy to provide logs to help investigate why Amethyst is failing on iOS 26.