Thanks purismforum. Both dig commands returned what seemed like normal results.
‘dig’ is new to me; what would be a sign of trouble in their output? Thanks, JAA84
You should be looking at the Answer section, all is ok if there is something in it.
Example :
;; ANSWER SECTION:
odrs.gnome.org. 900 IN CNAME openshift.gnome.org.
openshift.gnome.org. 900 IN A 8.43.85.29
openshift.gnome.org. 900 IN A 8.43.85.14
openshift.gnome.org. 900 IN A 8.43.85.13
If Dig works, then the DNS resolution looks to be working.
What did you get with the apt commands suggested by @quarnero?
No, it will not take you to Byzantium. It will upgrade Amber.
EDIT: Anyway, please wait until @purismforum or someone else confirms my suggestion (perhaps solution without searching for reason why this happened, as you described).
Unless you updated the apt source somehow. Frankly I am sad to say that I have been using Ubuntu for a while now, and that I always do apt update && apt upgrade almost daily with no issues.
Yes, this is the way to stay on the safe side, basic rule. And as it was very late for myself yesterday, let us try to help @jaa84 understand why regular (usually automated) updates are important:
Here is my Debian output, current one:
$ sudo apt update
Hit:1 http://security.debian.orgstable/updates InRelease
Hit:2 etc. All packages are up to date.
$ sudo apt upgrade apt
…
apt is already the newest version (1.8.2.1).
Calculating upgrade… Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
I tried debugging a similar issue two years ago. I finally gave up and stopped using gnome-software for the most part. It worked; I just kept getting erroneous messages.
I still get those, and similar, messages on both PureOS and Debian buster.
Thanks Quarnero. The Amber upgrade you recommended seems to have done the trick.
I didn’t need to remove and reinstall gnome-software.
By the way, I understand the importance of regular updates, and had been doing them faithfully until about a month ago, when I started getting the failed-to-download message. jaa84