https://paste.ee/p/0TPhE
Using 1.2.3 (2c79dcd).
This only happens when LambDynamicLights is enabled. Without it, it launches fine.

I... didn't build it correctly (build instead of shadowRemapJar).
Damn your non-standard build instructions /s

Well, the non-standard build instruction is to avoid libraries shadowing on Maven builds. I just wanted to avoid to pollute the Maven jar but the result is it's very confusing.