Revert "modules: add support for module replacement with disabledModules"

This reverts commit 3f2566689d for now.
Evaluation of the tested job got broken, blocking nixos-unstable.

lib/modules.nix

@@ -20,8 +20,7 @@ rec {
                 , prefix ? []
                 , # This should only be used for special arguments that need to be evaluated
                   # when resolving module structure (like in imports). For everything else,
-                  # there's _module.args. If specialArgs.modulesPath is defined it will be
-                  # used as the base path for disabledModules.
+                  # there's _module.args.
                   specialArgs ? {}
                 , # This would be remove in the future, Prefer _module.args option instead.
                   args ? {}
@@ -59,7 +58,10 @@ rec {
 
       closed = closeModules (modules ++ [ internalModule ]) ({ inherit config options; lib = import ./.; } // specialArgs);
 
-      options = mergeModules prefix (filterModules (specialArgs.modulesPath or "") closed);
+      # Note: the list of modules is reversed to maintain backward
+      # compatibility with the old module system.  Not sure if this is
+      # the most sensible policy.
+      options = mergeModules prefix (reverseList closed);
 
       # Traverse options and extract the option values into the final
       # config set.  At the same time, check whether all option
@@ -85,16 +87,6 @@ rec {
       result = { inherit options config; };
     in result;
 
-
- # Filter disabled modules. Modules can be disabled allowing
- # their implementation to be replaced.
- filterModules = modulesPath: modules:
-   let
-     moduleKey = m: if isString m then toString modulesPath + "/" + m else toString m;
-     disabledKeys = map moduleKey (concatMap (m: m.disabledModules) modules);
-   in
-     filter (m: !(elem m.key disabledKeys)) modules;
-
   /* Close a set of modules under the ‘imports’ relation. */
   closeModules = modules: args:
     let
@@ -119,13 +111,12 @@ rec {
       else {};
     in
     if m ? config || m ? options then
-      let badAttrs = removeAttrs m ["_file" "key" "disabledModules" "imports" "options" "config" "meta"]; in
+      let badAttrs = removeAttrs m ["imports" "options" "config" "key" "_file" "meta"]; in
       if badAttrs != {} then
         throw "Module `${key}' has an unsupported attribute `${head (attrNames badAttrs)}'. This is caused by assignments to the top-level attributes `config' or `options'."
       else
         { file = m._file or file;
           key = toString m.key or key;
-          disabledModules = m.disabledModules or [];
           imports = m.imports or [];
           options = m.options or {};
           config = mkMerge [ (m.config or {}) metaSet ];
@@ -133,10 +124,9 @@ rec {
     else
       { file = m._file or file;
         key = toString m.key or key;
-        disabledModules = m.disabledModules or [];
         imports = m.require or [] ++ m.imports or [];
         options = {};
-        config = mkMerge [ (removeAttrs m ["_file" "key" "disabledModules" "require" "imports"]) metaSet ];
+        config = mkMerge [ (removeAttrs m ["key" "_file" "require" "imports"]) metaSet ];
       };
 
   applyIfFunction = key: f: args@{ config, options, lib, ... }: if isFunction f then

lib/tests/modules.sh

@@ -99,14 +99,6 @@ checkConfigOutput 'true' "$@" ./define-enable.nix ./define-loaOfSub-if-foo-enabl
 checkConfigOutput 'true' "$@" ./define-enable.nix ./define-loaOfSub-foo-if-enable.nix
 checkConfigOutput 'true' "$@" ./define-enable.nix ./define-loaOfSub-foo-enable-if.nix
 
-# Check disabledModules with config definitions and option declarations.
-set -- config.enable ./define-enable.nix ./declare-enable.nix
-checkConfigOutput "true" "$@"
-checkConfigOutput "false" "$@" ./disable-define-enable.nix
-checkConfigError "The option .*enable.* defined in .* does not exist" "$@" ./disable-declare-enable.nix
-checkConfigError "attribute .*enable.* in selection path .*config.enable.* not found" "$@" ./disable-define-enable.nix ./disable-declare-enable.nix
-checkConfigError "attribute .*enable.* in selection path .*config.enable.* not found" "$@" ./disable-enable-modules.nix
-
 # Check _module.args.
 set -- config.enable ./declare-enable.nix ./define-enable-with-custom-arg.nix
 checkConfigError 'while evaluating the module argument .*custom.* in .*define-enable-with-custom-arg.nix.*:' "$@"

lib/tests/modules/default.nix

@@ -3,6 +3,5 @@
 {
   inherit (lib.evalModules {
     inherit modules;
-    specialArgs.modulesPath = ./.;
   }) config options;
 }

lib/tests/modules/disable-declare-enable.nix

@@ -1,5 +0,0 @@
-{ lib, ... }:
-
-{
-  disabledModules = [ ./declare-enable.nix ];
-}

lib/tests/modules/disable-define-enable.nix

@@ -1,5 +0,0 @@
-{ lib, ... }:
-
-{
-  disabledModules = [ ./define-enable.nix ];
-}

lib/tests/modules/disable-enable-modules.nix

@@ -1,5 +0,0 @@
-{ lib, ... }:
-
-{
-  disabledModules = [ "define-enable.nix" "declare-enable.nix" ];
-}