postgresql-10 is required.

docs/getting-started.rst

@@ -48,8 +48,12 @@ Package dependencies
 Software Heritage requires some dependencies that are usually packaged by your
 package manager. On Debian/Ubuntu-based distributions::
 
+  sudo apt-get install curl ca-certificates
   curl https://deb.nodesource.com/setup_8.x | sudo bash
-  sudo apt install python3 python3-venv libsvn-dev postgresql nodejs npm \
+  curl https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
+  sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
+  sudo apt update
+  sudo apt install python3 python3-venv libsvn-dev postgresql-10 nodejs npm \
                    libsystemd-dev
 
 Postgres