Setting up deb package sources failed

(Sorry but I will have to keep editing this very post when I reply as I am limited to 3 posts by topic as a beginner)

My distro is

It is the successor of Crunchbang (#!)
(https://www.bunsenlabs.org/
i’ on the latest version, that I keep updated on a regular basis.

So indeed commenting got me a little further;
I had to install postfix to meet a dependency; itself depended on ssl-cert that I installed too,
I rerun the script and got to:

[quote]…
Reading package lists…
Building dependency tree…
Reading state information…
postfix is already the newest version.
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:
yunohost : Depends: moulinette (>= 2.3.5.1) but it is not going to be installed
Depends: glances but it is not installable
Depends: netcat-openbsd but it is not installable
Depends: iproute but it is not installable
Depends: mariadb-server but it is not going to be installed or
mysql-server but it is not going to be installed
Depends: php5-mysql or
php5-mysqlnd but it is not going to be installed
Depends: slapd but it is not going to be installed
Depends: ldap-utils but it is not going to be installed
Depends: sudo-ldap but it is not going to be installed
Depends: libnss-ldapd but it is not installable
Depends: postfix-ldap but it is not installable
Depends: postfix-policyd-spf-perl but it is not installable
Depends: postfix-pcre but it is not installable
Depends: procmail but it is not installable
Depends: dovecot-ldap but it is not going to be installed
Depends: dovecot-lmtpd but it is not going to be installed
Depends: dovecot-managesieved but it is not going to be installed
Depends: dovecot-antispam but it is not going to be installed
Depends: fail2ban but it is not installable
Depends: nginx-extras (>= 1.6.2) but it is not going to be installed
Depends: php5-fpm but it is not going to be installed
Depends: php5-ldap but it is not going to be installed
Depends: php5-intl but it is not going to be installed
Depends: dnsmasq but it is not going to be installed
Depends: avahi-daemon but it is not installable
Depends: ssowat but it is not going to be installed
Depends: metronome but it is not going to be installed
Depends: rspamd (>= 1.2.0) but it is not going to be installed
Depends: rmilter (>= 1.7.0) but it is not going to be installed
Depends: redis-server but it is not going to be installed
Depends: opendkim-tools but it is not installable
Recommends: openssh-server but it is not going to be installed
Recommends: etckeeper but it is not installable
Recommends: php5-gd but it is not going to be installed
Recommends: php5-curl but it is not going to be installed
Recommends: php-gettext but it is not installable
Recommends: php5-mcrypt but it is not going to be installed
Recommends: python-pip but it is not installable
Recommends: unattended-upgrades but it is not going to be installed
Recommends: libdbd-ldap-perl but it is not installable
Recommends: libnet-dns-perl but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Failure !
The following error was caught during Yunohost installation :

Installation of Yunohost packages failed[/quote]

any quick suggestion?
thanks