My F45 builds of Cherrytree in Copr fail (F43-44 build successfully).

Excerpts from https://download.copr.fedorainfracloud.org/results/bcotton/cherrytree/fedora-rawhide-x86_64/10759266-cherrytree-future/builder-live.log.gz

Cherrytree upstream has confirmed in https://github.com/giuspen/cherrytree/issues/2889 that it is not related to Cherrytree's use of the library

In file included from /usr/include/giomm-2.4/giomm.h:44,
                 from /usr/include/gtkmm-3.0/gtkmm.h:99,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_main_win.h:31,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_actions.h:26,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_actions_edit.cc:24:
/usr/include/giomm-2.4/giomm/dbusactiongroup.h:32:7: error: conflicting declaration ‘using GDBusActionGroupClass = struct _GDBusActionGroupClass’
   32 | using GDBusActionGroupClass = struct _GDBusActionGroupClass;
      |       ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/giomm-2.4/giomm.h:44,
                 from /usr/include/gtkmm-3.0/gtkmm.h:99,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_main_win.h:31,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_actions.h:26,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_actions_file.cc:24:
/usr/include/giomm-2.4/giomm/dbusactiongroup.h:32:7: error: conflicting declaration ‘using GDBusActionGroupClass = struct _GDBusActionGroupClass’
   32 | using GDBusActionGroupClass = struct _GDBusActionGroupClass;
      |       ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/giomm-2.4/giomm.h:73:
/usr/include/giomm-2.4/giomm/emblem.h:31:7: error: conflicting declaration ‘using GEmblemClass = struct _GEmblemClass’
   31 | using GEmblemClass = struct _GEmblemClass;
      |       ^~~~~~~~~~~~
In file included from /usr/include/giomm-2.4/giomm.h:44,
                 from /usr/include/gtkmm-3.0/gtkmm.h:99,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_main_win.h:31,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_actions.h:26,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_actions_export.cc:24:
/usr/include/giomm-2.4/giomm/dbusactiongroup.h:32:7: error: conflicting declaration ‘using GDBusActionGroupClass = struct _GDBusActionGroupClass’
   32 | using GDBusActionGroupClass = struct _GDBusActionGroupClass;
      |       ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/giomm-2.4/giomm.h:73:
/usr/include/giomm-2.4/giomm/emblem.h:31:7: error: conflicting declaration ‘using GEmblemClass = struct _GEmblemClass’
   31 | using GEmblemClass = struct _GEmblemClass;
      |       ^~~~~~~~~~~~
In file included from /usr/include/giomm-2.4/giomm.h:44,
                 from /usr/include/gtkmm-3.0/gtkmm.h:99,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_main_win.h:31,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_actions.h:26,
                 from /builddir/build/BUILD/cherrytree-future-1.7.1-build/cherrytree-1.7.1/src/ct/ct_actions_find.cc:24:
/usr/include/giomm-2.4/giomm/dbusactiongroup.h:32:7: error: conflicting declaration ‘using GDBusActionGroupClass = struct _GDBusActionGroupClass’
   32 | using GDBusActionGroupClass = struct _GDBusActionGroupClass;
      |       ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/giomm-2.4/giomm.h:73:
/usr/include/giomm-2.4/giomm/emblem.h:31:7: error: conflicting declaration ‘using GEmblemClass = struct _GEmblemClass’
   31 | using GEmblemClass = struct _GEmblemClass;
      |       ^~~~~~~~~~~~

Reproducible: Always