> What's hard is accurately surveying the last 15 years of systems built on top of Linux's needlessly-complicated LRNG and making changes that don't violate the expectations of those systems.
Sounds like they need a compatibility or feature (cmdline) flag.
Add the flag and you can use the new improved system. Establish dates for when the old method will not be the default anymore (but can be used with the flag) and when it will be deprecated for good
That won‘t align with the never break the user mantra. And honestly I hate these timebomb solutions some API vendors put up. In a never breaking system you can‘t remove anything only add things or change stuff internally to make it work like before. They never said to get rid of /dev/random or /dev/urandom just that both would practically be the same. From reading about the problem and the different usecases and expectations it looks like it will stay like this for another decade or more.
Sounds like they need a compatibility or feature (cmdline) flag.
Add the flag and you can use the new improved system. Establish dates for when the old method will not be the default anymore (but can be used with the flag) and when it will be deprecated for good