Comment by AshamedCaptain

> Funnily enough grabbing some old .so files from the RHEL 7 install and dumping them into LD_LIBRARY_PATH also worked better than expected.

Why "better than expected"? I can run the entire userspace from Debian Etch on a kernel built two days ago... some kernel settings need to be changed (because of the old glibc! but it's not glibc's fault: it's the kernel who broke things), but it works.

> Now running stuff compiled on modern Ubuntu or RHEL 10 on the older OS, now that's a whole different story...

But this is a different problem, and no one makes promises here (not the kernel, not musl). So all the talk of statically linking with musl to get such type of compatibility is bullshit (at some point, you're going to hit a syscall/instruction/whatever that the newer musl does that the older kernel/hardware does not support).