Just doing an install on VMWare 5.5 of Ubuntu 22.04 and have been seeing curtin command in-target for over an hour.
I selected to update the installer before beginning the install and selected the standard server install (not the "minimal")
When I select View full log. I see new versions of packages being downloaded and installed. It seems to take a minute or more for each package to go through the preparing to unpack, unpacking and then setting up cycle. And it appears there are hundreds.
I've seen the blame be put on slow mirrors but not sure why it would be so painfully slow.
So what I've done now is choose the "Cancel update and reboot" option.
After the reboot I just ran apt-get update && apt-get -y dist-upgrade and it completes in an acceptable time.
Thanks for sharing this, I had the same annoying damn issue and it's NOT the mirrors because no network traffic is being sent according to the router.