Added a try-rerun-except block to grub-install (#1085)

* Added a try-rerun-except block to grub-install first with --removable and then without if it fails. I have a sneaky suspicion that it's due to USB drives being the destination medium, but I cannot confirm yet. I've also added peak_output=True and --debug to GRUB so we can catch the issues in the future.

* Fixed flake8 complaint

Author: Torxed

archinstall/lib/installer.py

@@ -832,12 +832,15 @@ def add_grub_bootloader(self, boot_partition :Partition, root_partition :Partiti
 		if has_uefi():
 			self.pacstrap('efibootmgr') # TODO: Do we need? Yes, but remove from minimal_installation() instead?
 			try:
-				SysCommand(f'/usr/bin/arch-chroot {self.target} grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=GRUB --removable')
-			except SysCallError as error:
-				raise DiskError(f"Could not install GRUB to {self.target}/boot: {error}")
+				SysCommand(f'/usr/bin/arch-chroot {self.target} grub-install --debug --target=x86_64-efi --efi-directory=/boot --bootloader-id=GRUB --removable', peak_output=True)
+			except SysCallError:
+				try:
+					SysCommand(f'/usr/bin/arch-chroot {self.target} grub-install --debug --target=x86_64-efi --efi-directory=/boot --bootloader-id=GRUB --removable', peak_output=True)
+				except SysCallError as error:
+					raise DiskError(f"Could not install GRUB to {self.target}/boot: {error}")
 		else:
 			try:
-				SysCommand(f'/usr/bin/arch-chroot {self.target} grub-install --target=i386-pc --recheck {boot_partition.parent}')
+				SysCommand(f'/usr/bin/arch-chroot {self.target} grub-install --debug --target=i386-pc --recheck {boot_partition.parent}', peak_output=True)
 			except SysCallError as error:
 				raise DiskError(f"Could not install GRUB to {boot_partition.path}: {error}")