Using aptitude since last clean install, I recently observed how big /var had grown. Starting around 100 Megabytes, it now stood at a whopping 2.5 Gigabytes. I suspected it was caused by aptitude's cache archive. Running du -sh /var confirmed it.
Deb files are stored in /var/cache/apt/archives. Aptitude's cache was now 2.3 Gigabytes in size. Time to trim.
I ran aptitude autoclean:
# aptitude autoclean
It took around 1 minute and reduced the cache by 1.4 Gigabytes. Still too much. I ran aptitude clean:
# aptitude clean
This purges pretty much everything. Check again and it was down to a manageable 263 Megabytes. Okay.
Keep an eye on aptitude. Its a disk space hog.