This one is the linked in @corradoventu’s bug report:
and it gave me the idea.
Does that mean, that 26.04 systems will still be falsely flagged as ineligible for Ubuntu Pro, despite above workaround? I have tested on 24.04 with the desktop-security-center snap, so that might explain why it works for me. I cannot test with 26.04, though. @corradoventu, can you?
But it looks like the next stage of the workaround could be a simple:
osr=/etc/os-release
if ! grep -Fq 'VERSION="26.04 LTS' "$osr"; then
sudo sed -ri.bak 's/(^(VERSION="26.04)/\1 LTS/' "$osr"
fi
unset osr
(just had a peek at the base-files package and only the VERSION needs changing)
The above is a very condensed way of saying – and doing–, make a backup copy of /etc/os-release and edit the line in the original file that starts with “VERSION=” and insert a space character and “LTS” so it looks like this:
VERSION="26.04 LTS (Resolute Raccoon)"
That’s what the Ubuntu Pro client looks for. But don’t forget to connect the Desktop Security Center to the proper plug, afterwards.