[ubuntu] Messed up migration of a dual boot on a SSD: broken Ubuntu boot

Hello,

I need some help to fix my non-booting Ubuntu. I have a Macbook Pro with a dual boot OS X / Ubuntu 16.04.3. I have recently bought a SSD. I have cloned the full HD disk with Clonezilla, changed the partition sizes and upgraded OS X on the new clone (/sdb2). I have also changed the cloned UUID of Ubuntu to try to avoid the confusion between the two Ubuntu clone.

I did a mistake formatting the older Ubuntu partitions too early (on disk /sda), and I am know left with an unbootable Ubuntu partition (/sdb4).

I tried to run Boot-Repair from an Ubuntu liveUSB but the situations is not better. Here is the generated boot-info: http://paste.ubuntu.com/26459686/

I can access the newly installed grub and also the rEFInd menu. There is (or at least there was before the Boot-Repair) a Bios-grub partition in /sdb6. Though, I can not find the boot
as advised by the Boot-Repair.

Here are screenshots of GParted (were /sda2 and /sdb2 are OS X partition).
sda.pngsdb.png

Do you have any idea what is going wrong here ?

Thank you :-)

Attached Images

• sda.png (53.8 KB)
• sdb.png (68.9 KB)