[bug] client crash on startup

[Siphalor]

Versions

Minecraft 1.16.5
TTLG: 2.0.0-alpha.2
Modpack: Tiny Tater Test Server (based on AOF) - latest

Description

On startup the game just crashes with the following log (relevant parts extracted):

https://hatebin.com/nrytqviayh

Complete log

https://paste.siphalor.de/?8ab77ea3639825bf#FM6KDdsamTFC65CgMZW8vGRcwqUAjHsETVhf4zM3zfFh

Additional context

This issue already appeared on 2.0.0-alpha.1 but was claimed to be fixed.

Wild guessing

This is caused by https://github.com/Dragonoidzero/Through-the-Looking-Glass/blob/6f98e312e365a1d9f5ae77b95337f1378a769662/src/main/java/azzy/fabric/lookingglass/util/EnumAdder.java#L22

I fear you're relying on a specific JRE functionality there that probably isn't available on OpenJDK