Hi,
I just tested installing avast on debian stretch (64bit) - and it installed smoothly and runs!
The one tiny thing which bit me, was that the path for 'scan' changed from '/bin' to '/usr/bin' (had the '/bin/scan' hardcoded) - but I think that's ok in a major version jump (and it's in the ChangeLog).
Thanks for resolving this!!
I guess that from now on the repositories (for Debian) will be named 'debian-$codename' ? (i.e. deb
http://deb.avast.com/lin/repo debian-buster release for the upcoming debian 10)