Grub cannot be installed (installer stops at 95%) [Solved]

[gmerguez]

Thank you so much, the system boots and seems to work just fine!
In order to make sure that I had not ruined anything in between, I repeated the whole process again:
1. Regular install with a clean hhd for getting the default partitions (failed at GRUB install, as expected).
2. New install without GRUB (post #8).
3. Chroot-rescue-scan - install GRUB without writing NVRAM - update-grub (post #4)

Rebooting, this time I took a closer look at the Boot-rescue menus: Booting into the new system worked. After spending some time searching about how to write the NVRAM entry, I finally did what I should have done earlier and tried just letting the system boot from the HDD, without doing anything to NVRAM: It actually booted just fine!
Actually, this may have been the case as early as post #6, I just did not try. Stupid. And most of all, grateful to the incredibly kind and patient help I experienced here.

[baldyeti]

It isn't the first time someone hits this issue, late in the installation process (and with no clear error message)

Which begs the question: wouldn't it be possible, in case of UEFI-type installation, for the installer to check upfront whether the nvram is likely to run out of available slots ?

just an improvement suggestion ...