Are you trying to update over Tor (sys-whonix)? If so, this is a common occurrence that is usually resolved by simply waiting a bit, then trying again later. (You can also try to speed it up by requesting a new circuit with Nyx in sys-whonix.)
Just to confirm, this is the Qubes Update tool found in the app menu under Qubes Tools > Qubes Update, right? Just want to make sure it’s not a GUI package manager inside of a template, for example.
But why? For what purpose? What do you hope to achieve with such a list?
The reason I ask is because it’s not entirely clear to me what you’re asking. For one thing, there’s more than one Qubes repo. You asked whether this has to be done in dom0. That depends on whether you want to know the contents of a dom0 repo or a domU repo. I guess my best guess to an answer to your question is simply to look here:
I don’t know what the first part means - “the directory that the gui
updater is using”.
The GUI in dom0 is defined in dom0 in /lib/python3.8/site-packages/qui.
Updating is currently done using salt, and the salt states are in
/srv/formulas/base/update-formula
The second part - what applications?
Why do you want to know this?
What will you do with this knowledge?
Explain what it is you are trying to do - it’s likely that you
are asking the wrong questions, looking for the wrong details, and if
these questions are answered, you will not be satisfied.
I never presume to speak for the Qubes team.
When I comment in the Forum or in the mailing lists I speak for myself.