How to know the version of some package to be installed by apt-get in advance?

Question

How to know the version of some package to be installed by apt-get in advance?

I see, I could make it by using apt-cache madison. But i does not work well all the time, for example, xenomai package. For details, see below.

##sucessfully
ubuntu:~$ apt-cache madison libcurl3
      libcurl3 | 7.47.0-1ubuntu2.14 | http://mirrors.aliyun.com/ubuntu xenial-updates/main amd64 Packages
      libcurl3 | 7.47.0-1ubuntu2.14 | http://mirrors.aliyun.com/ubuntu xenial-security/main amd64 Packages
      libcurl3 | 7.47.0-1ubuntu2 | http://mirrors.aliyun.com/ubuntu xenial/main amd64 Packages
    ubuntu:~$

##failed
ubuntu:~$ apt-cache madison xenomai
ubuntu:~$ #no output indeed!

Answer 1

this is manly because "madison" is a debian tool and not a ubuntu tool.
Please always use madison on https://qa.debian.org/madison.php

Your example xenomai is visible here
https://qa.debian.org/madison.php?package=xenomai&table=ubuntu