This ended up being the fix to needing to run autoreconf -fi multiple times:
https://github.com/c-ares/c-ares/commit/e73fb47
Which appears to not be specific to c-ares as we got the logic from:
https://github.com/fenrus75/powertop/pull/82
https://bugzilla.redhat.com/show_bug.cgi?id=1835638
After that, there is also the issue that the newer ax_code_coverage.m4
that is automatically pulled in is not API compatible as it removes
@CODE_COVERAGE_RULES@ which isn't too friendly, plus adds a slew of
additional .m4 dependencies that had to be imported.
And then finally, there is actually a bug in the latest
ax_code_coverage.m4 that quotes AC_MSG_ERROR() which causes older
autoconf/automake versions to barf.
https://github.com/c-ares/c-ares/commit/3883d99b05a845e4b40fc25c43ca83db70f4f20f#diff-fe38622a6c742be1bb93e6e65a0728f659114b3dc8d88172cb8844fa963418f9
I'm not sure where to report the last 2 issues.
