tce-load -i compiletc meson dbus-glib-dev gnome-desktop-dev upower-dev xmlto gettext

wget https://download.gnome.org/sources/gnome-session/40/gnome-session-40.0.tar.xz
https://gitweb.gentoo.org/repo/gentoo.git/tree/gnome-base/gnome-session/files/gnome-session-3.38.0-meson-Support-elogind.patch

cd gnome-session-40.0

patch -Np1 -i ../gnome-session-3.38.0-meson-Support-elogind.patch

mkdir build
cd build

CC="gcc -flto -mtune=generic -Os -pipe" CXX="g++ -flto -mtune=generic -Os -pipe -fno-exceptions -fno-rtti" meson --prefix=/usr/local --libexecdir=/usr/local/lib/gnome-session --localstatedir=/var --buildtype=plain -Dsystemd_journal=false -Dman=false -Ddocbook=false -Delogind=true -Dsystemd_session=disable -Dsystemd=false

ninja [0m 7.87s]
sudo ninja install

                gnome-session 40.0
                ====================

        prefix:                   /usr/local
        exec_prefix:              /usr/local/lib/gnome-session
        libdir:                   /usr/local/lib
        bindir:                   /usr/local/bin
        sbindir:                  /usr/local/sbin
        sysconfdir:               /usr/local/etc
        localstatedir:            /var
        datadir:                  /usr/local/share
        source code location:     /usr/src/gnome-session-40.0
        compiler:                 gcc
        cflags:                   
        Debug mode:               false
        Use *_DISABLE_DEPRECATED: false

        Session tracking:         elogind 
        Build Docbook:            false
        Build manpages:           false