I can verify that gimp
can be installed and that it works in a persistent live Ubuntu 18.04 LTS [family flavour, Lubuntu].

My test system was installed into an old hard disk drive, that I have connected via a USB3 to SATA adapter. I used mkusb to create the persistent live system.
I have run gimp
also in standard Ubuntu 18.04 LTS and it works also in a USB pendrive, if there is enough free space in the casper-rw
file or partition. You must activate the repository 'universe' for the gimp
package to be found and installed,
sudo add-apt-repository universe
Edit: Before giving up your current persistent live system, try to reboot.
If no luck, maybe it would be best to create a fresh persistent live system with mkusb, or
if your USB drive is big and fast enough to create an installed system in it, installed like into an internal drive but into a USB drive. Such a system can be portable enough (but not as portable as a persistent live system), and it is more flexible and stable, when we talk about installing program packages.
sudo apt update && sudo apt install gimp
– sudodus Jul 09 '18 at 15:44/cow
? Please check with the commanddf -h
, edit your original question to show the output (of the command). Indent each line of the output 4 spaces to render it as 'code' – sudodus Jul 09 '18 at 15:58atom
program and corresponding package do you want? There seems to be more than one, that are available in Ubuntu 18.04 LTS. – sudodus Jul 09 '18 at 16:23