I installed PCL using the following commands.
sudo add-apt-repository ppa:v-launchpad-jochen-sprickerhof-de/pcl
sudo apt-get update
sudo apt-get install libpcl-a
I had the same problem when I followed the steps mentioned on the website http://www.pointclouds.org/downloads/linux.html, for Ubuntu 18.
You simply need to run sudo apt install libpcl-dev
as bionic is not mentioned in the distributions (http://ppa.launchpad.net/v-launchpad-jochen-sprickerhof-de/pcl/ubuntu/dists/)