26th November 2016, 11:15
OK I fear then it isn't possible to use ubiquity to install here.
The only culprit here would be the ubiquity-casper package that includes some scripts for the live environment to come up.
Adding them is not trivial. You don't only need to install the package but also need to update-initramfs with the update-initramfs.distrib -u which generates a new initrd in /boot that needs to be copied over the one on the live sticks casper/initrd.lz.
Though this means also the live stick needs to be formatted as fat32 to write files to it which usually isn't the case when using dd to write the image to USB.
So in general we could try this aswell and I am pretty confident it will work then. Though it might be tough for you.
The only culprit here would be the ubiquity-casper package that includes some scripts for the live environment to come up.
Adding them is not trivial. You don't only need to install the package but also need to update-initramfs with the update-initramfs.distrib -u which generates a new initrd in /boot that needs to be copied over the one on the live sticks casper/initrd.lz.
Though this means also the live stick needs to be formatted as fat32 to write files to it which usually isn't the case when using dd to write the image to USB.
So in general we could try this aswell and I am pretty confident it will work then. Though it might be tough for you.