It is great to confirm that the latest version of Postgres cleanly builds on the latest Ubuntu without any errors or warnings. Hmmm, I wonder now if GGC 5 makes anything measurably run faster??
$ sudo apt-get install build-essential libreadline-dev zlib1g-dev flex bison libxml2-dev libxslt-dev libssl-dev
With this complete, you can then do an industrial strength build of PostgreSQL as per below:
$ tar -xvf postgresql-9.6.x.tar.bz2
$ cd postgresql-9.6.x
$ ./configure –with-libxml –with-libxslt –with-openssl