How to set a limit and clear Avocado cache?

[Philippe Mathieu-Daudé]

Hello,

Today I ran out of space in my /home, I ran the 'baobab' tool and while 
the first bigger directory was obvious to me (~/.ccache), the second 
wasn't: ~/avocado/data/cache/by_location/, with various GiB.

Note, this directory is not listed in my config...
$ avocado config | fgrep ${HOME}/avocado
$

I might already have asked on qemu-devel mailing list, but is there a 
way to set a particular location for the cache directory, different than 
my data directory where I keep the job-results log files?

From the doc, get_cache_dirs() "Returns the list of cache dirs, 
according to configuration and convention" but doesn't explain how to 
configure it:
https://avocado-framework.readthedocs.io/en/75.1/api/core/avocado.core.html#avocado.core.data_dir.get_cache_dirs

I searched if there was an Avocado command displaying cache use, and to 
eventually flush it, like ccache --cleanup/--clear options, but couldn't 
find any, so I ended calling a rmdir ~/avocado, which I know it is not 
correct, but saved me some headaches.

Is there a clean way to do this?

I see the clean_tmp_files() function, but no equivalent for the cache:
https://avocado-framework.readthedocs.io/en/75.1/api/core/avocado.core.html#avocado.core.data_dir.clean_tmp_files

Bonus question, can I set a size limit for the cache directory?

Thanks,

Phil.