Fix dependency merging of "all" component

Author: rvl

modules/package.nix

@@ -19,6 +19,8 @@ with lib;
 with types;
 
 let
+  haskellLib = let hl = import ../lib { inherit lib; haskellLib = hl; }; in hl;
+
   # This is just like listOf, except that it filters out all null elements.
   listOfFilteringNulls = elemType: listOf elemType // {
     # Mostly copied from nixpkgs/lib/types.nix
@@ -97,11 +99,11 @@ in {
     };
 
     components = let
-      componentType = check: submodule {
+      componentType = defaults: submodule {
         options = {
           depends = mkOption {
             type = listOfFilteringNulls unspecified;
-            default = [];
+            default = defaults.depends or [];
           };
           libs = mkOption {
             type = listOfFilteringNulls (nullOr package);
@@ -141,7 +143,7 @@ in {
           };
           doCheck = mkOption {
             type = bool;
-            default = check;
+            default = defaults.doCheck or false;
           };
           doCrossCheck = mkOption {
             type = bool;
@@ -151,35 +153,38 @@ in {
       };
     in {
       library = mkOption {
-        type = componentType false;
+        type = componentType {};
       };
       sublibs = mkOption {
-        type = attrsOf (componentType false);
+        type = attrsOf (componentType {});
         default = {};
       };
       foreignlibs = mkOption {
-        type = attrsOf (componentType false);
+        type = attrsOf (componentType {});
         default = {};
       };
       exes = mkOption {
-        type = attrsOf (componentType false);
+        type = attrsOf (componentType {});
         default = {};
       };
       tests = mkOption {
-        type = attrsOf (componentType config.doCheck);
+        type = attrsOf (componentType { inherit (config) doCheck; });
         default = {};
       };
       benchmarks = mkOption {
-        type = attrsOf (componentType false);
+        type = attrsOf (componentType {});
         default = {};
       };
-      all = mkOption {
-        type = componentType false;
-        default = let
-          componentTypes = [ "library" "sublibs" "foreignlibs" "exes" "tests" "benchmarks" ];
-        in {
-          depends = mkMerge (map (c: config.components.${c}.depends or []) componentTypes);
+      all = let
+        subComponentsDepends = sub: concatLists
+            (mapAttrsToList (_: c: c.depends or []) config.components.${sub} or {});
+        default = {
+          depends = config.components.library.depends ++
+            concatMap subComponentsDepends haskellLib.subComponentTypes;
         };
+      in mkOption {
+        type = componentType default;
+        inherit default;
         defaultText = "The merged dependencies of all other components";
       };
     };

test/tests.sh

@@ -36,4 +36,11 @@ nix-shell $NIX_BUILD_ARGS \
     --run 'echo CABAL_CONFIG=$CABAL_CONFIG && type -p ghc && cd with-packages && rm -rf dist-newstyle .ghc-environment* && cabal new-build'
 echo >& 2
 
+printf "*** Checking that a nix-shell works for cabal (doExactConfig component)...\n" >& 2
+nix-shell $NIX_BUILD_ARGS \
+    --pure ./default.nix \
+    -A with-packages.test-shell-dec \
+    --run 'echo CABAL_CONFIG=$CABAL_CONFIG && echo GHC_ENVIRONMENT=$GHC_ENVIRONMENT && cd with-packages && rm -rf dist-newstyle .ghc-environment* && cabal new-build'
+echo >& 2
+
 printf "\n*** Finished successfully\n" >& 2

test/with-packages/default.nix

@@ -21,6 +21,14 @@ let
       {
         packages.transformers-compat.components.library.doExactConfig = true;
       }
+
+      # vary component config for tests
+      {
+        packages.test-with-packages.components = {
+          all.doExactConfig = false;    # the default
+          library.doExactConfig = true; # not the default
+        };
+      }
     ];
   };
 
@@ -43,8 +51,10 @@ in
       # test with-packages
 
       printf "checking that the 'all' component works... " >& 2
-      echo ${package.components.all}
-      # echo >& 2
+      echo ${package.components.all} >& 2
+
+      printf "checking that the 'library' component works... " >& 2
+      echo ${package.components.library} >& 2
 
       printf "checking that the package env has the dependencies... " >& 2
       ${package.components.all.env}/bin/runghc ${./Point.hs}
@@ -65,4 +75,7 @@ in
   # Used for testing externally with nix-shell (../tests.sh).
   # This just adds cabal-install to the existing shells.
   test-shell = addCabalInstall packages.test-with-packages.components.all;
+
+  # A variant of test-shell with the component option doExactConfig enabled
+  test-shell-dec = addCabalInstall packages.test-with-packages.components.library;
 }