I'm experimentally rebuilding rawhide with the not-yet-released GCC 15 to see if anything breaks, and to help write the porting guide.  See https://fedoraproject.org/wiki/User:Dmalcolm/gcc-15

My test build with GCC 15 failed:
https://copr.fedorainfracloud.org/coprs/dmalcolm/gcc-15-smoketest-3.failed/build/8476054/

whereas my test build with GCC 14 succeeded:
https://copr.fedorainfracloud.org/coprs/dmalcolm/gcc-15-smoketest-3.failed.checker/build/8477609/

Looking at the failure logs e.g.
https://download.copr.fedorainfracloud.org/results/dmalcolm/gcc-15-smoketest-3.failed/fedora-rawhide-x86_64/08476054-TeXmacs/builder-live.log.gz

I see:

In file included from /builddir/build/BUILD/TeXmacs-2.1.2-build/TeXmacs-2.1.2-src/src/Kernel/Containers/hashtree.hpp:126,
                 from /builddir/build/BUILD/TeXmacs-2.1.2-build/TeXmacs-2.1.2-src/src/Data/String/converter.hpp:15:
/builddir/build/BUILD/TeXmacs-2.1.2-build/TeXmacs-2.1.2-src/src/Kernel/Containers/hashtree.cpp: In member function 'hashtree<K, V> hashtree<K, V>::operator[](K)':
/builddir/build/BUILD/TeXmacs-2.1.2-build/TeXmacs-2.1.2-src/src/Kernel/Containers/hashtree.cpp:97:14: error: 'class hashtree<K, V>' has no member named 'contains' [-Wtemplate-body]
   97 |   if (*this->contains (key)) return *this->children (key);
      |              ^~~~~~~~
/builddir/build/BUILD/TeXmacs-2.1.2-build/TeXmacs-2.1.2-src/src/Kernel/Containers/hashtree.cpp:97:44: error: 'class hashtree<K, V>' has no member named 'children' [-Wtemplate-body]
   97 |   if (*this->contains (key)) return *this->children (key);
      |                                            ^~~~~~~~
gmake[2]: *** [src/CMakeFiles/texmacs_body.dir/build.make:130: src/CMakeFiles/texmacs_body.dir/Data/Convert/Coq/parse_vernac.cpp.o] Error 1

Looks like another instance of https://fedoraproject.org/wiki/User:Dmalcolm/gcc-15#C++:_error_with_-Wtemplate-body


Reproducible: Always