Enable PostgreSQL PDO support on OS X

cd ~/Downloads
tar -jxvf php-5.5.20.tar.bz2
sudo mkdir -p /usr/include
sudo mv php-5.5.20 /usr/include/php
cd /usr/include/php
./configure --without-iconv
cd ext/pdo_pgsql
brew install autoconf
phpize
./configure --with-pdo-pgsql=/Applications/Postgres.app/Contents/Versions/9.4/
make
sudo cp pdo_pgsql.so /usr/lib/php/extensions/no-debug-non-zts-20121212

https://www.alistairphillips.com/apple/osx/php-pdo-pgsql/