Calamares lacks support for vfat (needed for EFI/UEFI) on Mac

[RalphBike]

Manjaro can currently not be installed on a Mac with UEFI with Calamares. The installer does not offer VFAT, the installation fails with this error message if another filesystem is used for the boot partition:

Boost.Python-Fehler in Job "bootloader".
<class 'subprocess.CalledProcessError'>
Command 'grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=Manjaro --force' returned non-zero exit status 1
Traceback:
  File "/usr/lib/calamares/modules/bootloader/main.py", line 289, in run
    prepare_bootloader(fw_type)

  File "/usr/lib/calamares/modules/bootloader/main.py", line 277, in prepare_bootloader
    install_grub(efi_directory, fw_type)

  File "/usr/lib/calamares/modules/bootloader/main.py", line 220, in install_grub
    "--force"])

  File "<string>", line 2, in <module>

The whole problem is described in this thread, however still not improved in Manjaro 17.0.2. https://forum.manjaro.org/t/first-install-help-me-to-get-going-please/21810/14

The workaround is:

1. Create and format the boot partition manually before the installation
2. Mount the partition manually at the right moment while Calamares is doing the installation.
3. Boot again with from USB
4. Mount /-partition
5. Modify fstab entry for boot-partition from xxx to vfat