You need ruby and fpm installed to create .deb package.
-m- optional. Set the maintainer's name, mail, etc. Default: user@hostname-v- optional. version of s3cmd. Default: 1.5.1.2-o- optional. Used to set org in the iteration of the package (example: wheezy1, myorg2, etc). Default: debian
Use build.sh with Jenkins or in your terminal.
You'll find your .deb in the _pkg directory.
$ ./build.sh -m 'John Smith' -o 'my_org' -v 1.5.1.2
[... many symbols ...]
Created package {:path=>"s3cmd-1.5.1.2-my_org1502052003-amd64.deb"}