On mac. Downloaded $ curl -O http://ftp.postgresql.org/pub/source/v9.6.9/postgresql-9.6.9.tar.bz2 and extracted it.
$ curl -O http://ftp.postgresql.org/pub/source/v9.6.9/postgresql-9.6.9.tar.bz2
Running $ ./configure --prefix=
$ ./configure --prefix=