tce-load -i compiletc meson gtkmm-dev libgtop-dev libhandy1-dev librsvg-dev itstool desktop-file-utils appstream-glib gettext

wget https://download.gnome.org/sources/gnome-system-monitor/40/gnome-system-monitor-40.0.tar.xz

cd gnome-system-monitor-40.0

mkdir build
cd build

CC="gcc -flto  -mtune=generic -Os -pipe" CXX="g++ -flto -mtune=generic -Os -pipe" meson --prefix=/usr/local --localstatedir=/var --libexecdir=/usr/local/lib --buildtype=plain -Dsystemd=false

[-fno-rtti fails]

ninja [0m 34.58s]
sudo ninja install

Configuration:

        Source code location:   /usr/src/gnome-system-monitor-40.0
        C Compiler:             gcc 10.2.0
        C++ Compiler:           gcc 10.2.0
        CFLAGS:                 ['-Wcast-align', '-Wchar-subscripts', '-Winline', '-Wmissing-declarations', '-Wpointer-arith', '-Wsign-compare', '-Wmissing-prototypes', '-Wnested-externs']
        CXXFLAGS:               ['-Wcast-align', '-Wchar-subscripts', '-Winline', '-Wmissing-declarations', '-Wpointer-arith', '-Wsign-compare']
        systemd support:        false
        wnck support:           false