tce-load -i compiletc intltool gtk3-dev gmime-dev gnutls-dev

cd pan-0.140

CC="gcc -flto -fuse-linker-plugin -march=i486 -mtune=i686 -Os -pipe" CXX="g++ -flto -fuse-linker-plugin -march=i486 -mtune=i686 -Os -pipe" ./configure --prefix=/usr/local --localstatedir=/var --with-gtk3 --with-gnutls

find . -name Makefile -type f -exec sed -i 's/-g -O2//g' {} \;

make
sudo make install

Configuration:

        Prefix:                 /usr/local
        Source code location:   .
        Compiler:               g++ -flto -fuse-linker-plugin -march=i486 -mtune=i686 -Os -pipe
        With D-Bus:             no
        With GMime 2.6+:        yes
        With GtkSpell:          no
        With GTK+ 3:            yes >= 3.0.0
        With WebKitGTK+:        no
        With GnuTLS:            yes (3.0.30)
        With libnotify:         no
        With GNOME Keyring:     no