Kernel 6.12 - booting hanged in real PREEMPT_RT mode

[Oleksa75]

Hello there!

As we know, the real big one for release 6.12 is the enabling of PREEMPT_RT, implementing real-time computing capabilities.

Kernel from Gentoo repos was compiled OK, but I am unable to boot with it - the process hanging with strange phrases smth like "group root:root is invalid".

Please, can you help me to build an investigation plan and find the root of the reason?

Thanks!