Document a minimum required kernel version?

[rosenhouse]

I have occasionally hit run-time bugs that seem to be a kernel dependency, or perhaps a mismatch between the kernel version of the host and the userspace libraries shipped in our docker container image (glibc etc).

I wonder if we should write down somewhere what we test with. Our build page gives a version of Clang and GCC, though this would be a run-time guidance, not build-time....