I am having trouble with conflicting bootloader options. In my flake I want to generate separate nix configs for bare metal machines and for Proxmox LXCs.
I have written two modules, each hidden behind enable options:
bare metal bootloader.nix
{ config, lib, ... }:
let
cfg = config.my.system.bootloader;
in
{
options = {
my.system.bootloader = {
enable = lib.mkOption {
type = lib.types.bool;
default = false;
description = "Enable bootloader settings";
};
};
};
config = lib.mkIf cfg.enable {
boot.loader.systemd-boot.enable = true;
boot.loader.systemd-boot.graceful = true;
boot.loader.systemd-boot.configurationLimit = 45;
boot.loader.efi.canTouchEfiVariables = true;
};
}
proxmox-lxc.nix
{ config, pkgs, lib, modulesPath, ... }:
let
cfg = config.my.system.proxmox-lxc;
in
{
options = {
my.system.proxmox-lxc = {
enable = lib.mkOption {
type = lib.types.bool;
default = false;
description = "Enable proxmox-lxc settings";
};
};
};
imports = [ (modulesPath + "/virtualisation/proxmox-lxc.nix") ];
config = lib.mkIf cfg.enable {
boot.isContainer = true;
# Suppress these units, since they do not work inside LXC
systemd.suppressedSystemUnits = [
"dev-mqueue.mount"
"sys-kernel-debug.mount"
"sys-fs-fuse-connections.mount"
];
};
}
Both default to disabled and I would only enable one at a time. Unfortunately I can’t even rebuild with both modules staged and disabled in my repo. This is the error I receive:
nixos rebuild error
error:
… while calling the 'head' builtin
at /nix/store/52hnnvpyni1n79ra4rqxdcswmd2w3823-source/lib/attrsets.nix:1534:13:
1533| if length values == 1 || pred here (elemAt values 1) (head values) then
1534| head values
| ^
1535| else
… while evaluating the attribute 'value'
at /nix/store/52hnnvpyni1n79ra4rqxdcswmd2w3823-source/lib/modules.nix:992:7:
991| // {
992| value = addErrorContext "while evaluating the option `${showOption loc}':" value;
| ^
993| inherit (res.defsFinal') highestPrio;
… while evaluating the option `system.build.toplevel':
… while evaluating definitions from `/nix/store/52hnnvpyni1n79ra4rqxdcswmd2w3823-source/nixos/modules/system/activation/top-level.nix':
… while evaluating the option `system.systemBuilderArgs':
… while evaluating definitions from `/nix/store/52hnnvpyni1n79ra4rqxdcswmd2w3823-source/nixos/modules/system/activation/top-level.nix':
… while evaluating the option `system.build.installBootLoader':
(stack trace truncated; use '--show-trace' to show the full, detailed trace)
error: The option `system.build.installBootLoader' is defined multiple times while it's expected to be unique.
Only one bootloader can be enabled at a time. This requirement has not
been checked until NixOS 22.05. Earlier versions defaulted to the last
definition. Change your configuration to enable only one bootloader.
Definition values:
- In `/nix/store/52hnnvpyni1n79ra4rqxdcswmd2w3823-source/nixos/modules/system/boot/loader/init-script/init-script.nix': <derivation init-script-builder.sh>
- In `/nix/store/52hnnvpyni1n79ra4rqxdcswmd2w3823-source/nixos/modules/system/boot/loader/systemd-boot/systemd-boot.nix': <derivation install-systemd-boot.sh>
Use `lib.mkForce value` or `lib.mkDefault value` to change the priority on any of these definitions.
My troubleshooting indicates that this is caused by the import of /virtualisation/proxmox-lxc.nix. The error disappears when I comment out the import of that external module, but that’s equivalent to commenting out my own module.
As I understand it, imports must be separate to config and therefore cannot be hidden behind a conditional lib.mkIf cfg.enable.
So how can I import /virtualisation/proxmox-lxc.nix for my Proxmox LXC hosts without conflicting with boot settings for bare metal machines? i.e. how can I have both of these modules in my repo simultaneously?