tce-load -i compiletc meson atkmm-dev pangomm-dev gtk4-dev

wget https://download.gnome.org/sources/gtkmm/4.12/gtkmm-4.12.0.tar.xz

cd gtkmm-4.12.0

mkdir build-lib
cd build-lib

CC="gcc -flto -mtune=generic -Os -pipe" CXX="g++ -flto -mtune=generic -Os -pipe -DNDEBUG" meson --prefix=/usr/local --localstatedir=/var --buildtype=plain -Dbuild-documentation=false

ninja [8m 14.17s]
sudo ninja install

gtkmm 4.12.0

         Maintainer mode: if-git-build (false)
       Compiler warnings: min (warning_level: 1, werror: false)
    Build deprecated API: true
Build HTML documentation: false
     Build demo programs: true
     Build test programs: true
Directories:
                  prefix: /usr/local
              includedir: /usr/local/include
         includegtkmmdir: /usr/local/include/gtkmm-4.0
                  libdir: /usr/local/lib
          gdkmmconfigdir: /usr/local/lib/gtkmm-4.0/include
          gtkmmconfigdir: /usr/local/lib/gtkmm-4.0/include
                   m4dir: /usr/local/lib/gtkmm-4.0/proc/m4
            pkgconfigdir: /usr/local/lib/pkgconfig
                 datadir: /usr/local/share
                  docdir: /usr/local/share/doc/gtkmm-4.0
              devhelpdir: /usr/local/share/devhelp/books/gtkmm-4.0
------
Build targets in project: 24

gtkmm 4.12.0

  User defined options
    buildtype          : plain
    localstatedir      : /var
    prefix             : /usr/local
    build-documentation: false