I just ran into this bug as well.
> First: I don't see the URL that fails
I wondered the same thing. The debug line only shows the name of the file to
save, not the url it's downloading from. So in
simple_cdd/tools/mirror_download.py I changed the log.debug line (54) as
follows:
log.debug("downloading: %s as %s", url, output)
which confirmed it was getting stuck on the extrafiles file for me as well.
As a workaround, I added the following line to acng.conf :
VfilePatternEx: /extrafiles$
and then restarted the service:
systemctl restart apt-cacher-ng
