Rebuilding a classic 20.04 Ubuntu

[melodie11]

Hi Kamilion!
I hope you are fine. Do you still maintain the project?

Here is what brings me : I have to rebuild a classic Ubuntu 20.04 to add a few packages needed, in order to install it to several machines.
I have done the same as I used to, and what happens I don't know, but the final result fails to boot in Virtualbox : the error message is that the /dev/sr0 has not been found! And that no cdrom was found.
However I have checked twice, the vbox machine should find it. The error ends also with the message that no filesystem was found (but the ISO seems fine, even looking into the filesystem of the ISO in isomaster).
Can you tell me how I can fix it?
Best regards,
Mélodie

[melodie11]

Hello, I accidently found what is wrong and how to fix it.
The generated ISO comes with two initrd files in the casper directory : one is certainly the old one (name, "initrd") and the new one is "initrd.lz".
I have modified using the tool isomaster, did two tests : in one I changed the line in grub.cfg to match initrd.lz (instead of initrd) and rebuilt the ISO (with a new name). The other test, I removed the "initrd" file from the casper directory, and renamed initrd.lz to initrd (without chaning the grub.cfg file). Both rebuilt ISO work.
I am keeping the second one as obviously it makes the ISO lighter.
Maybe could you change something in one of the python scripts to match the actual behavior?

[melodie11]

Hi, I have also found it necessary as well to modify the txt.cfg file in the isolinux directory of the ISO image accordingly to the grub.cfg file.

[melodie11]

The tutorial on how to install Customizer would also need a review, among several only one method works.