Snapcraft clears apt-get cache and download directory inside parts/application/ubuntu/ everytime user runs snapcraft clean ?? whats the benefit of that ??
Due to this user need to download approx 28mb (in my case) of apt cache (which include 7mb+ of icons which are useless or not required for building an application :D).
Like in a normal ubuntu system we do apt-get update to get new cache ,without deleting the older one , and do apt-get install somepackage (say its version 3) will not delete all apt downloaded packages cache to get new version of app, it keep the downloaded archives in cache which is usefull and saves your Internet data and bandwidth.
So this is a bug and should be resolved soon .
My suggestions for developers- create a new command to clean apt-archive and leave it up to the users if they wana delete old debs or not .
this will also allow him create packages when he will be off-line .
Indeed this is pretty daunting. It takes several minutes for apt to download its data, and it happens every time I switch across projects or touch files in a way that needs updating the offending part.
Since it's so big and slow, it should ideally cache this specific data outside of the part being built and share it across projects. Some sort of locking will be necessary, but it's much better to lock and wait than to redownload twice, potentially concurrently.