$ scanelf -n /usr/lib64/libgnutls.so.30.11.0 TYPE NEEDED FILE ET_DYN libz.so.1,libidn.so.11,libtasn1.so.6,libnettle.so.6,libhogweed.so.4,libgmp.so.10,libc.so.6 /usr/lib64/libgnutls.so.30.11.0 but no dep on it it seems it has a --without-libidn switch at configure.
Thanks! added idn USE.