I am running into this issue where I am trying to install postgresql-ll and I followed the instructions given at https://wiki.postgresql.org/wiki/Apt. I have also read previous posts related to this issue and they aren't running into same issue as I am.
When I run
apt-get install I get the following
sudo apt-get install postgresql-11 pgadmin4 E: Unable to locate package postgresql-11 E: Unable to locate package pgadmin4
I am not sure whether this error means that apt is unable to locate the repository or whether within the repository it is unable to locate the package
postgresql-11. Since both packages are not being found I am guessing it is unable to find the repository.
However, I have followed repository installation instructions as well as shown below:
cat /etc/apt/sources.list.d/pgdg.list deb http://apt.postgresql.org/pub/repos/apt xenial-pgdg main
Notice the second one has a trailing slash (wasn't sure if that made a difference). Anyone has any debugging suggestions or thoughts?