Adrian Siekierka
Comments
In general, one of the workarounds we have employed locally is to use lwjgl-jemalloc 3.2.1 with the rest of lwjgl being at 3.1.6 on Linux - this hasn't caused any issues so far, and may be a consideration-worthy option.
FoamFix developer here; that is, the mod that's causing the crash. Please update Forge to latest (latest!, not recommended) and let me know on https://github.com/asiekierka/FoamFix/issues if the issue persists.
Two important preceding cases:
Quasiconnectivity was originally an unintended behaviour of the engine. Due to the massive demand of it by players, it was kept in the PC version, albeit removed in the "Innovation" codebase. Grum has confirmed that it was, indeed, a "bug turned feature".
Minecart boosting was originally a bug in the engine related to minecart bounding boxes. Upon the addition of powered rails, which effectively deprecated them, it was removed.
In other words, Minecraft has had cases of both bugs becoming features and bugs not becoming features.
Indeed, which could be deemed a working, if disappointing, solution. However, the second part of the issue (parties who are not Mojang potentially being able to capture the data) is still present. Once you're sending data which can potentially identify a user, you should take extra care to ensure it's transmitted in a safe manner.
(Also, I do believe ways of uniquely identifying users without compromising their privacy should be looked into as well.)
Generally speaking, there are multiple places in the Minecraft codebase where "invalid namespaced string" exceptions are not being caught, causing the rest of the loading process to crash and burn horribly.