I did 2 steps from http://d-apt.sourceforge.net/

$ sudo wget http://master.dl.sourceforge.net/project/d-apt/files/d-apt.list -O /etc/apt/sources.list.d/d-apt.list

$ sudo apt-get update && sudo apt-get -y --allow-unauthenticated install --reinstall d-apt-keyring && sudo apt-get update

And now when I am trying to install dub I am getting next message:

root@66898:/# apt-get install dub
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 dub : Depends: dmd-bin but it is not going to be installed or
                dmd but it is not installable
       PreDepends: multiarch-support but it is not installable
E: Broken packages

On 2014-11-12, 5:39 AM, Suliman wrote:
> I did 2 steps from http://d-apt.sourceforge.net/
>

[snip]

> The following packages have unmet dependencies:
>   dub : Depends: dmd-bin but it is not going to be installed or
>                  dmd but it is not installable
>         PreDepends: multiarch-support but it is not installable
> E: Broken packages

OK, what does it complain about if you try to "apt-get install multiarch-support" ?

root@66898:~# apt-get install multiarch-support
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package multiarch-support is not available, but is referred to by another packag
e.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'multiarch-support' has no installation candidate

On Wednesday, 12 November 2014 at 16:19:23 UTC, Suliman wrote:
> root@66898:~# apt-get install multiarch-support
> Reading package lists... Done
> Building dependency tree
> Reading state information... Done
> Package multiarch-support is not available, but is referred to by another packag
> e.
> This may mean that the package is missing, has been obsoleted, or
> is only available from another source
>
> E: Package 'multiarch-support' has no installation candidate

If you haven't found the problem yet, please post:

1. what is the architecture of your machine? $ lscpu
2. what is the debian version? $ lsb_release -a

> If you haven't found the problem yet, please post:
>
> 1. what is the architecture of your machine? $ lscpu
> 2. what is the debian version? $ lsb_release -a

root@66898:~# lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
CPU(s):                4
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 45
Stepping:              7
CPU MHz:               623.437
Virtualization:        VT-x
root@66898:~#
root@66898:~# lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 6.0.9 (squeeze)
Release:        6.0.9
Codename:       squeeze
root@66898:~#


Debian image from vps.me

El 13/11/14 a les 07:29, Suliman via Digitalmars-d-learn ha escrit: ...
> Description:    Debian GNU/Linux 6.0.9 (squeeze)
...

packages on d-apt repository are created for multiarch systems, Debian 7.x.x and Ubuntu 12.04. Old stable Debian 6.x.x is not.

If you want to install dub deb package from d-apt on Debian 6.x.x I recomend you to install first the all-in-one dmd deb package from dlang.org: <http://downloads.dlang.org/releases/2014/dmd_2.066.1-0_amd64.deb>
then try to install dub deb package again. You can download it from here: <http://sourceforge.net/projects/d-apt/files/pool/main/d/dub/dub_0.9.22-0_amd64.deb/download>

I cannot assure that you will be able to install this dub deb package because it is designed for multi-arch systems.

Regards,
-- 
Jordi Sayol

You are right, after updating Debian to 7.7 dub was installed successfully