Since glibc 2.2, the function res_querydomain(3) is implemented as a define to `__res_querydomain`. Due to this implementation detail, using `AC_CHECK_LIB` with a symbol name of "res_querydomain" will cause a linking failure and thus fail to detect its availability. This is why right now, we try to detect availability of `__res_querydomain` instead. Unfortunately, this may break on other platforms where there is no `__res_querydomain` but only the function without leading underscores. To fix this, we can perform another `AC_CHECK_LIB([resolv], [res_querydomain], ...)` call in case where the other one was not found and only raise an error if both symbols weren't found. Signed-off-by: Patrick Steinhardt <ps@xxxxxx> --- configure.ac | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index 4bf5aea..cb9d921 100644 --- a/configure.ac +++ b/configure.ac @@ -411,7 +411,8 @@ if test "$enable_gss" = yes; then fi dnl libdnsidmap specific checks -AC_CHECK_LIB([resolv], [__res_querydomain], , AC_MSG_ERROR(res_querydomain needed)) +AC_CHECK_LIB([resolv], [__res_querydomain], , + AC_CHECK_LIB([resolv], [res_querydomain], , AC_MSG_ERROR(res_querydomain needed))) AC_ARG_ENABLE([ldap], [AS_HELP_STRING([--disable-ldap],[Disable support for LDAP @<:default=detect@:>@])]) -- 2.20.1
