We have a testcase meta/lib/oeqa/sdk/cases/buildiptables.py which tries to build vanilla iptables using SDK, however this fails with musl since there are patches e.g. http://git.openembedded.org/openembedded-core/tree/meta/recipes-extended/iptables/iptables/0001-fix-build-with-musl.patch otherwise the build will fail. So vanilla compiles wont work. I think we have to device a way to use the patched sources from build area to test compile it. That way we will always have chance to compile with out errors.
We *could* patch iptables but a simpler solution would be to change iptables to something else.
Currently I'm not able to reproduce neither test a a possible fix due this Bug 11741
Patch sent to the list https://patchwork.openembedded.org/patch/141496/
you also need https://patchwork.openembedded.org/patch/141620/ to complete the fix
Additional work will be also needed to change "meta/lib/oeqa/runtime/cases/buildiptables.py" so moving this to M3
Serie sent to the list https://patchwork.openembedded.org/series/7615/
Merge on master: http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=37e0cd0e917ad14f62770417d7f4fc8764b95f77 http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=aac343acc01ea275e05acd8ccf0e6f73581d535a