# Troubleshooting

The five rebuild errors a Nomarchy user is most likely to hit, with copy-paste fixes. If your error isn't here, the [Options Reference](OPTIONS.md) and [Migration Guide](MIGRATION.md) cover most other surfaces.

---

## 1. `error: The option 'X' is already declared in multiple modules`

**Looks like:**

```
error: The option `services.foo.enable' is already declared in multiple modules:
  - /nix/store/…-source/modules/foo.nix
  - /nix/store/…-source/core/system/foo.nix
```

**Cause:** Two modules — usually one of yours and one of Nomarchy's — both `mkOption` the same path. Nix can't merge two declarations of the *same option*; it can only merge two *values* for one option.

**Fix:** Find the duplicate. If it's yours and Nomarchy's, delete yours; Nomarchy already declares it. If it's two of yours, delete one. To grep:

```bash
grep -rn "options\..*foo\.enable" /etc/nixos
```

---

## 2. `error: attribute 'X' missing`

**Looks like:**

```
error: attribute 'nomarchy' missing
       at /etc/nixos/system.nix:7:5:
            7|     nomarchy.system.formFactor = "laptop";
```

**Cause:** You're setting `nomarchy.*` options but didn't import the Nomarchy modules. The flake's `nixosModules.system` declares the option namespace; without the import, the option doesn't exist.

**Fix:** In your `/etc/nixos/flake.nix`, make sure both modules are in the system's `modules = [ … ]` list:

```nix
modules = [
  nomarchy.nixosModules.system
  ./system.nix
  ./hardware-selection.nix
];
```

The home side is the same shape — `nomarchy.nixosModules.home` plus your `./home.nix`. See [MIGRATION.md](MIGRATION.md) for the full skeleton.

---

## 3. Stylix target conflict

**Looks like:**

```
error: The option `stylix.targets.gtk.enable' has conflicting definition values:
  - In `/nix/store/…/stylix.nix': true
  - In `/etc/nixos/home.nix': false
Use `lib.mkForce' or `lib.mkDefault' to resolve.
```

**Cause:** Stylix's per-target options are `bool`, not `enum`, so two equally-priority `true`/`false` values from two modules collide. Nomarchy's theming engine sets most targets to `true` via `mkDefault`, so the conflict almost always means *you* set one without `mkDefault`.

**Fix:** Wrap your override in `lib.mkForce`:

```nix
stylix.targets.gtk.enable = lib.mkForce false;
```

If you want the default-on behavior back, just delete your line — Nomarchy's default fires automatically.

---

## 4. home-manager `backupFileExtension` churn

**Looks like:** every rebuild leaves another `~/.config/foo/bar.conf.hm-bak` next to the file home-manager just wrote, until your `~/.config` is half backups.

**Cause:** home-manager refuses to overwrite files it didn't itself write; it backs them up first. Nomarchy's flake sets `backupFileExtension = "hm-bak"` (see `flake.nix:161,210`) so the first rebuild after a fresh ISO install doesn't fail — but every subsequent rebuild then re-backs-up the same files because the previous backup is still there.

**Fix:** After the first successful rebuild, delete the backups:

```bash
find ~/.config -name '*.hm-bak' -print -delete
```

If churn continues, you have a config under `~/.config/<app>/` that home-manager wants to manage but you've also touched by hand. Either let home-manager own it (don't edit by hand; use `nomarchy.*` options or `~/.config/nomarchy/overrides/`) or delete the home-manager declaration if you want the file to remain user-mutable.

---

## 5. impermanence path missing after a wipe

**Looks like:** after enabling `nomarchy.system.impermanence.enable = true;` and rebooting, an app forgets state — Bluetooth pairings vanish, NetworkManager forgets Wi-Fi, GPG keys are gone — or the rebuild itself errors with:

```
error: The path '/persist' does not exist
```

**Cause:** Impermanence requires (a) a `/persist` mountpoint that survives the boot wipe, and (b) every directory you want to keep must be in the persistence list. Nomarchy persists the basics in `core/system/impermanence.nix:46-72` (NetworkManager, Bluetooth, fprint, SSH host keys, the user's `.ssh` / `.gnupg` / Documents / Downloads / Pictures / Videos / Projects). Anything else you care about — Steam library, Flatpak data, custom dotfiles — must be added.

**Fix:** Make sure `/persist` is mounted (check `mount | grep persist`). Then add the missing path in your `system.nix`:

```nix
environment.persistence."/persist".users.nomarchy.directories = [
  ".local/share/Steam"
  ".var/app"             # flatpak data
  ".local/share/keyrings"  # already in Nomarchy defaults — example only
];
```

Per-app data lives in `~/.local/share/<app>` or `~/.var/app/<id>` (flatpak); check the app's docs. After adding, rebuild and reboot — the path is created on the next mount of `/persist`.

---

## Where to look next

- **Option reference:** [docs/OPTIONS.md](OPTIONS.md) — every `nomarchy.*` setting.
- **Existing-NixOS install:** [docs/MIGRATION.md](MIGRATION.md) — how to layer Nomarchy onto a working NixOS without reformatting.
- **Repo layout:** [docs/STRUCTURE.md](STRUCTURE.md) — where each module lives.
- **Roadmap:** [docs/ROADMAP.md](ROADMAP.md) — what's planned and what's shipped.