gnutls can not be built on s390x at the moment.
The error message is:
[  145s] make[4]: Leaving directory
'/home/abuild/rpmbuild/BUILD/gnutls-3.7.7/lib'
[  145s] make[4]: Entering directory
'/home/abuild/rpmbuild/BUILD/gnutls-3.7.7/lib'
[  145s] ./fipshmac > .libs/.gnutls.hmac-t && mv .libs/.gnutls.hmac-t
.libs/.gnutls.hmac
[  145s] *** stack smashing detected ***: terminated
[  145s] /usr/bin/bash: line 1: 20445 Aborted                 ./fipshmac >
.libs/.gnutls.hmac-t
[  145s] make[4]: *** [Makefile:3433: .libs/.gnutls.hmac] Error 134
[  145s] make[4]: Leaving directory
'/home/abuild/rpmbuild/BUILD/gnutls-3.7.7/lib'
[  145s] make[4]: *** Waiting for unfinished jobs....
[  145s] make[4]: Entering directory
'/home/abuild/rpmbuild/BUILD/gnutls-3.7.7/lib'
[  145s] /usr/bin/bash ../libtool  --tag=CXX   --mode=link g++ -I./includes
-I./includes -O2 -g -m64 -fmessage-length=0 -D_FORTIFY_SOURCE=2
-fstack-protector -funwind-tables -fasynchronous-unwind-tables -fPIE
-no-undefined -version-info 30:0:0 -pie -Wl,-z,now -Wl,-z,relro -o
libgnutlsxx.la -rpath /usr/lib64 libgnutlsxx_la-gnutlsxx.lo libgnutls.la 
[  145s] libtool: link: g++  -fPIC -DPIC -shared -nostdlib
/usr/lib64/gcc/s390x-suse-linux/12/../../../../lib64/crti.o
/usr/lib64/gcc/s390x-suse-linux/12/crtbeginS.o  .libs/libgnutlsxx_la-gnutlsxx.o
  -Wl,-rpath -Wl,/home/abuild/rpmbuild/BUILD/gnutls-3.7.7/lib/.libs
./.libs/libgnutls.so -L/usr/lib64 -ljitterentropy -lz -lp11-kit -lidn2
-lunistring -lpthread -ldl -ltasn1 -lnettle -lhogweed -lgmp
-L/usr/lib64/gcc/s390x-suse-linux/12
-L/usr/lib64/gcc/s390x-suse-linux/12/../../../../lib64 -L/lib/../lib64
-L/usr/lib/../lib64
-L/usr/lib64/gcc/s390x-suse-linux/12/../../../../s390x-suse-linux/lib
-L/usr/lib64/gcc/s390x-suse-linux/12/../../.. -lstdc++ -lm -lgcc_s -lc -lgcc_s
/usr/lib64/gcc/s390x-suse-linux/12/crtendS.o
/usr/lib64/gcc/s390x-suse-linux/12/../../../../lib64/crtn.o  -O2 -g -m64
-fstack-protector -Wl,-z -Wl,now -Wl,-z -Wl,relro   -Wl,-soname
-Wl,libgnutlsxx.so.30 -o .libs/libgnutlsxx.so.30.0.0
[  145s] libtool: link: (cd ".libs" && rm -f "libgnutlsxx.so.30" && ln -s
"libgnutlsxx.so.30.0.0" "libgnutlsxx.so.30")
[  145s] libtool: link: (cd ".libs" && rm -f "libgnutlsxx.so" && ln -s
"libgnutlsxx.so.30.0.0" "libgnutlsxx.so")
[  145s] libtool: link: ( cd ".libs" && rm -f "libgnutlsxx.la" && ln -s
"../libgnutlsxx.la" "libgnutlsxx.la" )
[  145s] make[4]: Leaving directory
'/home/abuild/rpmbuild/BUILD/gnutls-3.7.7/lib'
[  145s] make[3]: *** [Makefile:2903: all-recursive] Error 1
[  145s] make[2]: *** [Makefile:2507: all] Error 2
[  145s] make[1]: *** [Makefile:2258: all-recursive] Error 1
[  145s] make: *** [Makefile:2183: all] Error 2

https://build.opensuse.org/package/live_build_log/openSUSE:Factory:zSystems/gnutls/standard/s390x

From my point of view, the hint " *** stack smashing detected ***: terminated"
is the problem. Therefore, we should have a buffer overflow.