rmadison is a command to check package version available in all supported Debian release. This is a very useful command in case you are searching for a latest packages to install on your current Debian release.
In my case, I was trying to search for the latest xfce4 as current xfce4 version on my Debian Buster is 4.12.5 which which was released way back in year 2015.
$ rmadison xfce4
-bash: rmadison: command not found
Solution
Command rmadison is available through package devscripts. So installing this package will solve your problem
$ sudo apt install devscripts
This will install a bunch of things, so don’t be shocked. Currently the size and space the package needs is
Need to get 59.5 MB of archives.
After this operation, 147 MB of additional disk space will be used.
Verify if it is working
Do your check, such as rmadison xfce4 in my case.
$ rmadison xfce4
xfce4 | 4.10.1 | oldoldstable | source, all
xfce4 | 4.12.3 | oldstable | source, all
xfce4 | 4.12.5 | stable | source, all
xfce4 | 4.14 | testing | source, all
xfce4 | 4.14 | unstable | source, all
I will be taking the package from testing to be installed on my Buster. In case you want to do the same, you can refer this official tutorial by Debian team.