All, One of OpenDMARC’s users has commented that on the musl c library, the defines NETDB_SUCCESS and NETDB_INTERNAL are absent. While we could add: +#ifndef NETDB_INTERNAL +#define NETDB_INTERNAL (-1) +#endif To our own code, this feels like something autoconf should be able to test for and do for us. But I can’t seem to figure out how, without running AC_COMPILE_IFELSE. If that’s the answer, I’m willing to try it (or, as above, just add the ifdefine to our code), I just want to make sure I’m not missing something obvious. I’ve had to do some autoconf-bashing since we got a bug report to support 2.70, so it’s making me want to understand the WHOLE THING. Which is turning out to be a journey. -Dan