qemu build patch instructions

building 2.10: https://github.com/Cisco-Talos/pyrebox/issues/49 (I don't know if we support this right now)

2.5 is known to work

if you patch it to run against the glibc (as of this writing which is 2.28)

https://patchwork.openembedded.org/patch/137497/

https://gerrithub.io/c/spdk/qemu/+/385308