Build OpenConnect

apt update
apt install -y \
  autoconf autogen automake autopoint bison build-essential curl dash dns-root-data \
  gawk gettext git-core gperf gtk-doc-tools guile-2.2-dev libev-dev libgtk-3-dev \
  libidn2-0-dev libp11-kit-dev libtasn1-6-dev libtomcrypt-dev libtool libtspi-dev \
  libunbound-dev libunistring-dev libxml2-dev nettle-dev ninja-build python3-pip \
  texinfo texlive texlive-extra-utils vim wget
python3 -m pip install meson

git clone http://gitlab.com/gnutls/gnutls.git -b 3.6.16 ~/gnutls --depth 1
cd ~/gnutls
./bootstrap
./configure
make -j$(nproc)
make install

git clone https://github.com/p11-glue/p11-kit -b 0.24.0 ~/p11-kit --depth 1
cd ~/p11-kit
meson build
meson compile -C build
meson install -C build

git clone https://github.com/cernekee/stoken.git -b v0.92 ~/stoken --depth 1
cd ~/stoken
./autogen.sh
./configure
make -j$(nproc)
make install

mkdir -p /etc/vpnc
curl -L "https://gitlab.com/openconnect/vpnc-scripts/raw/master/vpnc-script" > /etc/vpnc/vpnc-script
chmod +x /etc/vpnc/vpnc-script

git clone git://git.infradead.org/users/dwmw2/openconnect.git ~/openconnect --depth 1
cd ~/openconnect
./autogen.sh
./configure
make -j$(nproc)
make install
ldconfig