My setup has multiple hard drives. The target drive was an SSD drive residing on
/dev/sdc. Trying to perform a complete re-install of either 18.04 or 17.10 from a flash drive was failing with an error:
grub-install /dev/sda failed
I already had 16.04 installed there, and decided to install over it (letting the installer to wipe the disk). I chose "use the entire disk and create LVM", and the installer failed with the error above. I tried the 17.10 installer and had the same issue.
After trying multiple workarounds suggested on the forums (boot-repair, GPT, Fast Boot, Secure boot, etc.) and none solving the problem, thinking about why is it trying to install grub onto
/dev/sda instead of
/dev/sdc I decided to try to disconnect all hard drives but that one.
As soon as I had just the SSD drive, it installed without a hitch.
I have no idea why it was trying to install grub onto
/dev/sda. Perhaps it's a bug in the installer. 2 years earlier I installed onto the same drive on the same system from 16.04 installer without a problem.
FYI, my SSD was set to be the first drive to boot from in BIOS, except it wasn't connected as a first SATA drive, which should make no difference.
Hope this helps someone.
edit: and I have just noticed the installer botched it even more. It created 1GB Swap partition, for a 24GB RAM installed. Yickes. I had to go to live CD, install and use kvpm to reduce the root lvm partition and extend swap.