When Manjaro updates a Linux kernel, it also needs to update grub. pacman / yay handle the package updates (as well as grub config update) automatically. But If I dual booted NixOS alongside Manjaro, would updating generations, kernels, and grub on one distro interfere with grub on the other? I am trying to anticipate a potential conflict if I were to try to dual boot Manjaro and NixOS.
Additionally, how practical would it be to dual boot Manjaro and NixOS on separate root partitions but which share a /home/ directory? Would NixOS’s Home Manager configured for /home/ pose a conflict to another Linux distro sharing the same partition for /home/?
Yes, unless you also mounted the Nix store to Majaro at /nix, because many of your XDG/dotfiles will be replaced with symlinks to read-only files within the Nix store. I would also assume there are other negative ripple effects if you just mount /nix but take no other action to make that Manjaro partition aware of Nix, so please don’t take that a suggested action.
The NixOS manual seems to suggest that the NixOS bootloader will essentially take over:
BIOS systems:
If there are other operating systems running on the machine before installing NixOS, the boot.loader.grub.useOSProber option can be set to true to automatically add them to the grub menu.
UEFI systems
With systemd-boot, you should not need any special configuration to detect other installed systems. With GRUB, set boot.loader.grub.useOSProber to true , but this will only detect windows partitions, not other Linux distributions. If you dual boot another Linux distribution, use systemd-boot instead.