Comment 2 for bug 1229488

This affects Ubuntu 14.04 64 bit also. Booting live media off USB2, installing to USB3 enclosure, resulted in an empty EFI partition on the target, and the new grub.cfg file copied to the host's internal EFI partition, leaving both target and host unbootable.
Same machine as above with secure boot disabled, target was a USB3 enclosure with a 256G SSD, partitioned with gdisk before the installation was attempted. The partitions were:
start 2048 4095 +1M grub-bios
efi 4096 614399 +300M boot
root1 614400 53043199 +25G
root2 53043200 105471999 +25G
Data 105472000 449404927 +163G
Not formatted before the installation. At installation, the grub-bios partition was unused (just present for future use), and while the efi partition was selected as efi, but the format button never became active, and the format checkoff never allowed a selection either. The root1 was selected for the /, and the bootloader device was selected as sdc (the target) BECAUSE THE SDC2 PARTITION was not even a choice (only sdc and sdc3 were choices). The installation finished normally, but had the following problems:
1) target's efi partition was left empty,
 2) host's efi files were updated, no problem for the .efi loaders, but the grub.cfg now used the hd2,gpt3 for the configfile command, which is not present after the target is removed.
 3)A NVRAM entry on the host was deleted. No changes at all were expected on the host, and while the removal of the shim boot entry did not cause any problems since I had a grubx64 entry also, this unwanted change is an error.
 4) The bootloader for a removable media like USB is not expected to have ANY nvram entry, and is expected to be in /EFI/Boot/bootx64.efi. A properly working install to USB should set up the shim or grubx64 that way.
    Easy enough to fix, copy the host's EFI files to the target (they were correct for the target after altering the disk number), and restore the host's grub.cfg file (I've learned to keep a copy around of the good file). Or use boot-repair I guess, since there are now 214 pages of forum activity there.
  Creating portable Ubuntu systems on USBs should never leave the UEFI host unbootable!