Hello,
I did exactly what you suggested:

sudo apt update && sudo apt upgrade -y && sudo apt dist-upgrade -y && sudo apt-get clean

Then I got the message that all packages were up-to-date and no package was added nor updated.
When trying to install

sudo apt-get install indi-full gsc

I again receive message that package gsc cannot be found...

Helmut Zimmermann
Cologne/Germany

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