Building perl-XML-LibXML with GCC 14 fails here:
https://build.opensuse.org/package/live_build_log/openSUSE:Factory:Staging:Gcc7/perl-XML-LibXML/standard/x86_64

Due to (exhaustive list of errors):

perl-libxml-mm.c: In function ‘PmmDumpRegistry’:
perl-libxml-mm.c:142:32: error: passing argument 2 of ‘xmlHashScan’ from incompatible pointer type [-Wincompatible-pointer-types]
  142 |                 xmlHashScan(r, PmmRegistryDumpHashScanner, NULL);
      |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~
      |                                |
      |                                void (*)(void *, void *, xmlChar *) {aka void (*)(void *, void *, unsigned char *)}
In file included from /usr/include/libxml2/libxml/parser.h:16,
                 from perl-libxml-mm.h:20,
                 from perl-libxml-mm.c:26:
/usr/include/libxml2/libxml/hash.h:213:57: note: expected ‘xmlHashScanner’ {aka ‘void (*)(void *, void *, const unsigned char *)’} but argument is of type ‘void (*)(void *, void *, xmlChar *)’ {aka ‘void (*)(void *, void *, unsigned char *)’}
  213 |                                          xmlHashScanner f,
      |                                          ~~~~~~~~~~~~~~~^
perl-libxml-mm.c: In function ‘PmmUnregisterProxyNode’:
perl-libxml-mm.c:234:51: error: passing argument 3 of ‘xmlHashRemoveEntry’ from incompatible pointer type [-Wincompatible-pointer-types]
  234 |         if( xmlHashRemoveEntry(PmmREGISTRY, name, PmmRegistryHashDeallocator) )
      |                                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~
      |                                                   |
      |                                                   void (*)(void *, xmlChar *) {aka void (*)(void *, unsigned char *)}
/usr/include/libxml2/libxml/hash.h:160:47: note: expected ‘xmlHashDeallocator’ {aka ‘void (*)(void *, const unsigned char *)’} but argument is of type ‘void (*)(void *, xmlChar *)’ {aka ‘void (*)(void *, unsigned char *)’}
  160 |                            xmlHashDeallocator f);
      |                            ~~~~~~~~~~~~~~~~~~~^
perl-libxml-mm.c: In function ‘PmmCloneProxyNodes’:
perl-libxml-mm.c:301:45: error: passing argument 2 of ‘xmlHashCopy’ from incompatible pointer type [-Wincompatible-pointer-types]
  301 |         reg_copy = xmlHashCopy(PmmREGISTRY, PmmRegistryHashCopier);
      |                                             ^~~~~~~~~~~~~~~~~~~~~
      |                                             |
      |                                             void * (*)(void *, xmlChar *) {aka void * (*)(void *, unsigned char *)}
/usr/include/libxml2/libxml/hash.h:208:56: note: expected ‘xmlHashCopier’ {aka ‘void * (*)(void *, const unsigned char *)’} but argument is of type ‘void * (*)(void *, xmlChar *)’ {aka ‘void * (*)(void *, unsigned char *)’}
  208 |                                          xmlHashCopier f);
      |                                          ~~~~~~~~~~~~~~^

See the meta bug#1220571 for more info.