FAIL: installing grub to target devices

Today deployment is constantly failing with MAAS 2.6.2. I’ve tried recommissioning and went through a live DVD of Gparted and wiped the storages to be sure. Still, I can’t get past this:

start: cmd-install/stage-curthooks/builtin/cmd-curthooks/install-grub: installing grub to target devices
setup grub on target /tmp/tmplwfmv7xv/target
Found primary UEFI ESP: sda-part1
finish: cmd-install/stage-curthooks/builtin/cmd-curthooks/install-grub: FAIL: installing grub to target devices
finish: cmd-install/stage-curthooks/builtin/cmd-curthooks/configuring-bootloader: FAIL: configuring target system bootloader
finish: cmd-install/stage-curthooks/builtin/cmd-curthooks: FAIL: curtin command curthooks
Traceback (most recent call last):
File “/curtin/curtin/commands/main.py”, line 202, in main
ret = args.func(args)
File “/curtin/curtin/commands/curthooks.py”, line 1770, in curthooks
builtin_curthooks(cfg, target, state)
File “/curtin/curtin/commands/curthooks.py”, line 1736, in builtin_curthooks
setup_grub(cfg, target, osfamily=osfamily)
File “/curtin/curtin/commands/curthooks.py”, line 623, in setup_grub
for dev_id in uefi_find_grub_device_ids(storage_cfg_odict)])
File “/curtin/curtin/commands/curthooks.py”, line 560, in uefi_find_grub_device_ids
if item[‘type’] == ‘mount’ and item[‘path’] == ‘/boot/efi’:
KeyError: ‘path’
‘path’
Stderr: ‘’

Previous deployment that worked used: curtin: Installation started. (19.3-26-g82f23e3d-0ubuntu1~18.04.1)
This failing one uses: curtin: Installation started. (20.1-2-g42a9667f-0ubuntu1~18.04.1)

The production is still running on ~30 hosts, but 2 that needed a redeployment are now uncapable of coming back online due to this.