How to install SchoolTool 2.0 on Debian?

[Csanyi Pal <csanyipal@gmail.com>]

Hi,

I wish to install on my Debian GNU/Linux testing/sid system the
SchoolTool 2.0: http://book.schooltool.org/install-2_0.html 

I realise that that I can't follow steps:

$ sudo add-apt-repository ppa:schooltool-owners/dev
$ sudo apt-get update

$ sudo apt-get install schooltool

because on debian there isn't such command:
add-apt-repository

$ sudo add-apt-repository ppa:schooltool-owners/dev
sudo: add-apt-repository: command not found

however if I edit my sources.list:
deb-src ppa:schooltool-owners/dev

and run
$ sudo aptitude update
I get messages:

E: Malformed line 25 in source list /etc/apt/sources.list (dist)
E: Malformed line 25 in source list /etc/apt/sources.list (dist)
E: The list of sources could not be read.
E: Malformed line 25 in source list /etc/apt/sources.list (dist)
E: The list of sources could not be read.
E: Malformed line 25 in source list /etc/apt/sources.list (dist)
E: Couldn't read list of package sources

So is there any solution on Debian to install SchoolTool 2.0?

-- 
Regards from Pal