ok folks:
what is the shell command to clear the apt package cache?

apt-get clean

This is on the man page

man page is LAST option ;-)
thanks

In my case I was unable to access synaptic, apt-get or aptitude until I used apt-get clean. Thank for the help.

Note: This is a 7 year old thread...

What you describe points to their being not enough space on the / partition. Unless the cache was huge, then clearing it may only be a temporary solution. If you have /var mounted on it's own partition you might not have allocated enough space there.

I have a small HDD for my linux system with two partitions one for / and /home as below:
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 14G 6.6G 6.7G 50% /
udev 3.7G 4.0K 3.7G 1% /dev
tmpfs 1.5G 1.2M 1.5G 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 3.7G 940K 3.7G 1% /run/shm
/dev/sda2 51G 11G 39G 21% /home

I do think it was due to a large cache that I this problem. If this occurs again that I will move /var to its own partition or expand /.

I did notice that it was a old post, does not mean that the information provide was not beneficial.

Agreed!