Below are my build instructions for GnuPG 2.2.3, released on November 20th, 2017. These instructions are built for a headless Ubuntu 14.04 LTS server (and have also been tested on Ubuntu 15.10/16.04/16.10/17.04).
If you prefer, you may use the below install script to install GnuPG 2.2.x by running the following commands:
curl -OL "https://gist.githubusercontent.com/vt0r/a2f8c0bcb1400131ff51/raw/c692d1751dbd91b066a9096508b10bd85b4d264a/install-gnupg22.sh" && sudo -H bash ./install-gnupg22.sh
apt-get -y install libgnutls-dev bzip2 make gettext texinfo gnutls-bin build-essential libbz2-dev zlib1g-dev libncurses5-dev libsqlite3-dev libldap2-dev || apt-get -y install libgnutls28-dev bzip2 make gettext texinfo gnutls-bin build-essential libbz2-dev zlib1g-dev libncurses5-dev libsqlite3-dev libldap2-dev
Note: To clean up from the older GnuPG 2.1.x builds, you probably want to delete /var/src/gnupg21
entirely.
mkdir -p /var/src/gnupg22 && cd /var/src/gnupg22
gpg --list-keys
gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 249B39D24F25E3B6 04376F3EE0856959 2071B08A33BD3F06 8A861B1C7EFD60D9
wget -c https://www.gnupg.org/ftp/gcrypt/libgpg-error/libgpg-error-1.27.tar.gz && \
wget -c https://www.gnupg.org/ftp/gcrypt/libgpg-error/libgpg-error-1.27.tar.gz.sig && \
gpg --verify libgpg-error-1.27.tar.gz.sig && tar -xzf libgpg-error-1.27.tar.gz && \
cd libgpg-error-1.27/ && ./configure && make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/libgcrypt/libgcrypt-1.8.1.tar.gz && \
wget -c https://www.gnupg.org/ftp/gcrypt/libgcrypt/libgcrypt-1.8.1.tar.gz.sig && \
gpg --verify libgcrypt-1.8.1.tar.gz.sig && tar -xzf libgcrypt-1.8.1.tar.gz && \
cd libgcrypt-1.8.1 && ./configure && make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/libassuan/libassuan-2.4.4.tar.bz2 && \
wget -c https://www.gnupg.org/ftp/gcrypt/libassuan/libassuan-2.4.4.tar.bz2.sig && \
gpg --verify libassuan-2.4.3.tar.bz2.sig && tar -xjf libassuan-2.4.4.tar.bz2 && \
cd libassuan-2.4.4 && ./configure && make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/libksba/libksba-1.3.5.tar.bz2 && \
wget -c https://www.gnupg.org/ftp/gcrypt/libksba/libksba-1.3.5.tar.bz2.sig && \
gpg --verify libksba-1.3.5.tar.bz2.sig && tar -xjf libksba-1.3.5.tar.bz2 && \
cd libksba-1.3.5 && ./configure && make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/npth/npth-1.5.tar.bz2 && \
wget -c https://www.gnupg.org/ftp/gcrypt/npth/npth-1.5.tar.bz2.sig && \
gpg --verify npth-1.5.tar.bz2.sig && tar -xjf npth-1.5.tar.bz2 && \
cd npth-1.5 && ./configure && make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/pinentry/pinentry-1.0.0.tar.bz2 && \
wget -c https://www.gnupg.org/ftp/gcrypt/pinentry/pinentry-1.0.0.tar.bz2.sig && \
gpg --verify pinentry-1.0.0.tar.bz2.sig && tar -xjf pinentry-1.0.0.tar.bz2 && \
cd pinentry-1.0.0 && ./configure --enable-pinentry-curses --disable-pinentry-qt4 && \
make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/gnupg/gnupg-2.2.3.tar.bz2 && \
wget -c https://www.gnupg.org/ftp/gcrypt/gnupg/gnupg-2.2.3.tar.bz2.sig && \
gpg --verify gnupg-2.2.3.tar.bz2.sig && tar -xjf gnupg-2.2.3.tar.bz2 && \
cd gnupg-2.2.3 && ./configure && make && make install
echo "/usr/local/lib" > /etc/ld.so.conf.d/gpg2.conf && ldconfig -v