Below are my build instructions for GnuPG 2.2.10, released on August 30th, 2018. These instructions are built for a headless Ubuntu 18.04 LTS server (and have also been tested on Ubuntu 14.04/16.04).
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/e0d2011d7b89bfe5b83c3f29f21949fb21354dd9/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-1.32.tar.gz && \
wget -c https://www.gnupg.org/ftp/gcrypt/libgpg-error/libgpg-error-1.32.tar.gz.sig && \
gpg --verify libgpg-error-1.32.tar.gz.sig && tar -xzf libgpg-error-1.32.tar.gz && \
cd libgpg-error-1.32/ && ./configure && make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/libgcrypt/libgcrypt-1.8.3.tar.gz && \
wget -c https://www.gnupg.org/ftp/gcrypt/libgcrypt/libgcrypt-1.8.3.tar.gz.sig && \
gpg --verify libgcrypt-1.8.3.tar.gz.sig && tar -xzf libgcrypt-1.8.3.tar.gz && \
cd libgcrypt-1.8.3 && ./configure && make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/libassuan/libassuan-2.5.1.tar.bz2 && \
wget -c https://www.gnupg.org/ftp/gcrypt/libassuan/libassuan-2.5.1.tar.bz2.sig && \
gpg --verify libassuan-2.5.1.tar.bz2.sig && tar -xjf libassuan-2.5.1.tar.bz2 && \
cd libassuan-2.5.1 && ./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-1.6.tar.bz2 && \
wget -c https://www.gnupg.org/ftp/gcrypt/npth/npth-1.6.tar.bz2.sig && \
gpg --verify npth-1.6.tar.bz2.sig && tar -xjf npth-1.6.tar.bz2 && \
cd npth-1.6 && ./configure && make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/pinentry/pinentry-1.1.0.tar.bz2 && \
wget -c https://www.gnupg.org/ftp/gcrypt/pinentry/pinentry-1.1.0.tar.bz2.sig && \
gpg --verify pinentry-1.1.0.tar.bz2.sig && tar -xjf pinentry-1.1.0.tar.bz2 && \
cd pinentry-1.1.0 && ./configure --enable-pinentry-curses --disable-pinentry-qt4 && \
make && make install && cd ../
wget -c https://www.gnupg.org/ftp/gcrypt/gnupg/gnupg-2.2.10.tar.bz2 && \
wget -c https://www.gnupg.org/ftp/gcrypt/gnupg/gnupg-2.2.10.tar.bz2.sig && \
gpg --verify gnupg-2.2.10.tar.bz2.sig && tar -xjf gnupg-2.2.10.tar.bz2 && \
cd gnupg-2.2.10 && ./configure && make && make install
echo "/usr/local/lib" > /etc/ld.so.conf.d/gpg2.conf && ldconfig -v
Looks like we both had a lot of the same ideas, @loizoskounios. I forked this super handy script by @vt0r and did some of what you did, as well as building in the ability to grant it sudo privileges using the pkexec function in most Linux desktop environments, so there's never any password tracks left in the terminal history.
It's available here for anyone that wants to put it to work, and I'm happy to get any comments or suggestions for improvements in the comments to meet any use cases I didn't already consider.