You can use apt-list -a <packagename>
to see the versions of said package that are available to download. On Ubuntu 18.04 (WSL):
$ apt list -a libssl-dev
The output is as follows:
Listing... Done
libssl-dev/bionic-updates,bionic-security 1.1.1-1ubuntu2.1~18.04.5 amd64
libssl-dev/bionic 1.1.0g-2ubuntu4 amd64
These are the versions of libssl-dev
that are available through Ubuntu's package repository. The version you are trying to install (1.0.2a) is not available for installation on Ubuntu 18.04 using apt
. If you must have that specific version of libssl-dev
, then there are alternative ways of installing it. It shouldn't hurt to try one of the newer versions, though.