clan services: use service modules from clan-core by default

Users will use clan-core services first before making their own. Therefore this is a better default. Also it allow us to simplify rendering of our docs

lib/clanTest/flake-module.nix

@@ -205,9 +205,6 @@ in
                 nixpkgs
                 nix-darwin
                 ;
-              # By default clan.directory defaults to self, but we don't
-              # have a sensible default for self here
-              self = throw "set clan.directory in the test";
             };
             modules = [
               clan-core.modules.clan.default

lib/default.nix

@@ -31,7 +31,7 @@ lib.fix (
     # ------------------------------------
     # ClanLib functions
     evalClan = clanLib.callLib ./modules/inventory/eval-clan-modules { };
-    inventory = clanLib.callLib ./modules/inventory { };
+    inventory = clanLib.callLib ./modules/inventory { clan-core = self; };
     modules = clanLib.callLib ./modules/inventory/frontmatter { };
     test = clanLib.callLib ./test { };
     # Custom types

lib/modules/clan/module.nix

@@ -238,7 +238,7 @@ in
           imports = [
             ../inventoryClass/builder/default.nix
             (lib.modules.importApply ../inventoryClass/service-list-from-inputs.nix {
-              inherit localModuleSet flakeInputs clanLib;
+              inherit flakeInputs clanLib localModuleSet;
             })
             {
               inherit inventory directory;

lib/modules/inventory/default.nix

@@ -1,6 +1,12 @@
-{ lib, clanLib }:
+{
+  lib,
+  clanLib,
+  clan-core,
+}:
 let
-  services = clanLib.callLib ./distributed-service/inventory-adapter.nix { };
+  services = clanLib.callLib ./distributed-service/inventory-adapter.nix {
+    inherit clan-core;
+  };
 in
 {
   inherit (services) mapInstances;

lib/modules/inventory/distributed-service/inventory-adapter.nix

@@ -12,10 +12,11 @@
 {
   lib,
   clanLib,
+  clan-core,
   ...
 }:
 let
-  resolveModule = import ./resolveModule.nix { inherit lib; };
+  resolveModule = import ./resolveModule.nix { inherit lib clan-core; };
 in
 {
   mapInstances =

lib/modules/inventory/distributed-service/resolveModule.nix

@@ -1,19 +1,12 @@
-{ lib }:
+{ lib, clan-core }:
 {
   moduleSpec,
   flakeInputs,
   localModuleSet,
 }:
 let
-  resolvedModuleSet =
+  inputName = if moduleSpec.input == null then "<clan>" else moduleSpec.input;
-    # If the module.name is self then take the modules defined in the flake
+  inputError = throw ''
-    # Otherwise its an external input which provides the modules via 'clan.modules' attribute
-    if moduleSpec.input == null then
-      localModuleSet
-    else
-      let
-        input =
-          flakeInputs.${moduleSpec.input} or (throw ''
     Flake doesn't provide input with name '${moduleSpec.input}'
 
     Choose one of the following inputs:
@@ -29,15 +22,24 @@ let
     ...
     - module.input = "${moduleSpec.input}"
 
-          '');
+  '';
-        clanAttrs =
+  resolvedModuleSet =
-          input.clan
+    # If the module.name is self then take the modules defined in the flake
-            or (throw "It seems the flake input ${moduleSpec.input} doesn't export any clan resources");
+    # Otherwise its an external input which provides the modules via 'clan.modules' attribute
+    let
+      input =
+        if moduleSpec.input == null then
+          clan-core
+        else if moduleSpec.input == "self" then
+          { clan.modules = localModuleSet; }
+        else
+          flakeInputs.${moduleSpec.input} or inputError;
     in
-      clanAttrs.modules;
+    input.clan.modules
+      or (throw "flake input ${moduleSpec.input} doesn't export any clan services via the `clan.modules` output attribute");
 
   resolvedModule =
     resolvedModuleSet.${moduleSpec.name}
-      or (throw "flake doesn't provide clan-module with name ${moduleSpec.name}");
+      or (throw "flake input '${inputName}' doesn't provide clan-module with name ${moduleSpec.name}");
 in
 resolvedModule