Attempting to detect whether we have a gethostbyname_r() with 6 arguments is fatal with gcc14. We jump straight to the 5 argument check which is correct when building with XPG6. diff -wpruN --no-dereference '--exclude=*.orig' a~/configure.ac a/configure.ac --- a~/configure.ac 1970-01-01 00:00:00 +++ a/configure.ac 1970-01-01 00:00:00 @@ -5778,26 +5778,8 @@ AH_TEMPLATE([HAVE_GETHOSTBYNAME_R], AC_CHECK_FUNC([gethostbyname_r], [AC_DEFINE([HAVE_GETHOSTBYNAME_R]) - AC_MSG_CHECKING([gethostbyname_r with 6 args]) OLD_CFLAGS=$CFLAGS CFLAGS="$CFLAGS $MY_CPPFLAGS $MY_THREAD_CPPFLAGS $MY_CFLAGS" - AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ -# include - ]], [[ - char *name; - struct hostent *he, *res; - char buffer[2048]; - int buflen = 2048; - int h_errnop; - - (void) gethostbyname_r(name, he, buffer, buflen, &res, &h_errnop) - ]])],[ - AC_DEFINE([HAVE_GETHOSTBYNAME_R]) - AC_DEFINE([HAVE_GETHOSTBYNAME_R_6_ARG], [1], - [Define this if you have the 6-arg version of gethostbyname_r().]) - AC_MSG_RESULT([yes]) - ],[ - AC_MSG_RESULT([no]) AC_MSG_CHECKING([gethostbyname_r with 5 args]) AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ # include @@ -5836,7 +5818,6 @@ AC_CHECK_FUNC([gethostbyname_r], AC_MSG_RESULT([no]) ]) ]) - ]) CFLAGS=$OLD_CFLAGS ], [ AC_CHECK_FUNCS([gethostbyname])