Cannot Make any installations

[sbiyyala]

I am reasonably new to Linux Ubuntu. I am using ubuntu 12.04. I am unable to make even small installations
eg: $ sudo apt-get install tree

Output ::
---------------------------------------------
Reading package lists...
Building dependency tree...
Reading state information...
tree is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
2 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]? Setting up qmail (1.06-4) ...

The hostname -f command returned: $1

Your system needs to have a fully qualified domain name (fqdn) in
order to install the var-qmail packages.

Installation aborted.

dpkg: error processing qmail (--configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of qmail-run:
qmail-run depends on qmail (>= 1.06-2.1); however:
Package qmail is not configured yet.
dpkg: error processing qmail-run (--configure):
dependency problems - leaving unconfigured

Errors were encountered while processing:
qmail
qmail-run

No apport report written because MaxReports is reached already
No apport report written because MaxReports is reached already
E: Sub-process /usr/bin/dpkg returned an error code (1)

----------------------------------------------
I have spent quite a lot of time and am clueless. Please help.

-

[zvacet]

Try with


sudo dpkg --configure -a

[sbiyyala]

Hello, thanks. But I got the same exact result ::

Setting up qmail (1.06-4) ...

The hostname -f command returned: $1

Your system needs to have a fully qualified domain name (fqdn) in
order to install the var-qmail packages.

Installation aborted.

dpkg: error processing qmail (--configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of qmail-run:
qmail-run depends on qmail (>= 1.06-2.1); however:
Package qmail is not configured yet.
dpkg: error processing qmail-run (--configure):
dependency problems - leaving unconfigured
Errors were encountered while processing:
qmail
qmail-run

[johnathansmith]

Do you add some new "sources" in update manager recently?

[Lasall]

Hi sbiyyala,

edit your /etc/hostname and setup your hostname.

Verify it with:

hostname -f

Regards
Lasall