How to find out "unmet dependencies"

[Thomas Kaiser]

Hello All

I try to install "build-essential" and get the following error:

live at media1:~$ sudo apt-get install build-essential
Reading package lists... Done
Building dependency tree... 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.

Since you only requested a single operation it is extremely likely that
the package is simply not installable and a bug report against
that package should be filed.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
   build-essential: Depends: g++ (>= 4:4.0) but it is not going to be 
installed
E: Broken packages
live at media1:~$

How can I find out WHY g++ will not be installd? Or To which package 
does the "unmet dependencies" reference?

Yes, here are my sources.list:
## Uncomment the following two lines to fetch updated software from the 
network
deb http://li.archive.ubuntu.com/ubuntu breezy main restricted
deb-src http://li.archive.ubuntu.com/ubuntu breezy main restricted

## Uncomment the following two lines to fetch major bug fix updates produced
## after the final release of the distribution.
deb http://li.archive.ubuntu.com/ubuntu breezy-updates main restricted
deb-src http://li.archive.ubuntu.com/ubuntu breezy-updates main restricted

## Uncomment the following two lines to add software from the 'universe'
## repository.
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
#deb http://li.archive.ubuntu.com/ubuntu breezy universe
#deb-src http://li.archive.ubuntu.com/ubuntu breezy universe

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
#deb http://li.archive.ubuntu.com/ubuntu breezy-backports main 
restricted universe multiverse
#deb-src http://li.archive.ubuntu.com/ubuntu breezy-backports main 
restricted universe multiverse

deb http://security.ubuntu.com/ubuntu breezy-security main restricted
deb-src http://security.ubuntu.com/ubuntu breezy-security main restricted

#deb http://security.ubuntu.com/ubuntu breezy-security universe
#deb-src http://security.ubuntu.com/ubuntu breezy-security universe


Hope somebody can help

Thomas

-- 
http://www.kaiser-linux.li