On an riscv64 emulated system with ACPI grub-install fails.
After enabling debug output I see the following log:
efivar: linux.c:464 device_get(): No such file or directory: could not access /sys/block/nvme1n1/device/driver
efivar: util.h:324 get_file(): No such file or directory: could not open file "/sys/devices/pci0000:00/firmware_node/path" for reading
efivar: util.h:324 get_file(): No such file or directory: could not open file "/sys/devices/pci0000:00/firmware_node/hid" for reading
efivar: linux-acpi.c:63 parse_acpi_hid_uid(): No such file or directory: could not read devices/pci0000:00/firmware_node/hid
efivar: linux.c:509 device_get(): No such file or directory: parsing pci_root failed
efivar: creator.c:194 efi_va_generate_file_device_path_from_esp(): No such file or directory: could not get ESP disk info
efivar: creator.c:349 efi_generate_file_device_path_from_esp(): No such file or directory: could not generate File DP from ESP
efibootmgr.c: efi.c:389 make_linux_load_option(): No such file or directory: efi_generate_file_device_path_from_esp() = -1 (failed)
efibootmgr.c: efibootmgr.c:321 make_var(): No such file or directory: make_linux_load_option() failed
efibootmgr.c: efibootmgr.c:370 make_var(): No such file or directory: Could not set variable
Could not prepare Boot variable: No such file or directory
There is a bug in device_get() that leads to exiting after one of the parsers failing instead of continuing with the next parser.
I have created an upstream merge request
https://github.com/rhboot/efivar/pull/246
and a Debian merge request
https://salsa.debian.org/efi-team/efivar/-/merge_requests/13.
The package efivar - 37-6ubuntu3~ppa1 is available in ppa:xypron/gnu-efi.