socklen_t.m4 uses the AC_TRY_COMPILE macro that is labeled obsolete and replaced trivially with a AC_COMPILE_IFELSE construct. This prevents autoreconf --warnings=all,error from succeeding.
Created attachment 11942 [details] trivial patch replacing obsolete macro with non-obsolete replacement I'm surprised I missed this when I previously submitted a patch to update the autoconf macros. Anyhow, after this change autoreconf --warnings=all,error will complete successfully for me. Configure appeared to run fine with the regenerated configure script.
Thanks for pointing that out and for the patch. Applied to git.