[root@nixos:/mnt]# nixos-install --show-trace
building the configuration in /mnt/etc/nixos/configuration.nix...
/nix/store/adb4a3qqbvvlddbmjzfsm6x3qiq99762-nixos-system-hp-laptop-21.05.1353.c06613c25df
copying channel...
installing the boot loader...
setting up /etc...
/etc/tmpfiles.d/journal-nocow.conf:26: Failed to resolve specifier: uninitialized /etc detected, skipping
All rules containing unresolvable specifiers will be skipped.
updating GRUB 2 menu...
Warning: os-prober will be executed to detect other bootable partitions.
It's output will be used to detect bootable binaries on them and create new boot entries.
grub-probe: error: cannot find a GRUB drive for /dev/sdb1. Check your device.map.
lsblk: /dev/mapper/no*[0-9]: not a block device
lsblk: /dev/mapper/raid*[0-9]: not a block device
lsblk: /dev/mapper/disks*[0-9]: not a block device
installing the GRUB 2 boot loader on /dev/sda...
Installing for i386-pc platform.
/nix/store/g6v6q3nrgiaxqa9p9zivykp8vqr3mazi-grub-2.06-rc1/sbin/grub-install: warning: cannot open directory `/nix/store/g6v6q3nrgiaxqa9p9zivykp8vqr3mazi-grub-2.06-rc1/share/locale': No such file or directory.
/nix/store/g6v6q3nrgiaxqa9p9zivykp8vqr3mazi-grub-2.06-rc1/sbin/grub-install: warning: this GPT partition label contains no BIOS Boot Partition; embedding won't be possible.
/nix/store/g6v6q3nrgiaxqa9p9zivykp8vqr3mazi-grub-2.06-rc1/sbin/grub-install: warning: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and their use is discouraged..
/nix/store/g6v6q3nrgiaxqa9p9zivykp8vqr3mazi-grub-2.06-rc1/sbin/grub-install: error: will not proceed with blocklists.
/nix/store/nvycxmg4g2q5jyqdxfvkgi95sqs48iw3-install-grub.pl: installation of GRUB on /dev/sda failed: No such file or directory

# Use the systemd-boot EFI boot loader.
  # boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;
  boot.loader.grub.enable = true;
  boot.loader.grub.devices = [ "/dev/sda" ];
  # boot.loader.grub.efiInstallAsRemovable = true;
  boot.loader.grub.efiSupport = true;
  boot.loader.grub.useOSProber = true;