haskell-generic-builder: simplify "package.conf.d" management

The builder creates a temporary package.conf.d database in $TMP that
contains everything required to build the current package (i.e. the
transitive closure of the package's propagated build inputs). These
files are no longer installed, however, we just install the package.conf
file for the package we're actually building. This means that
package.conf.d directory in $out won't have collisions anymore, which
simplifies the with-packages-wrapper.nix a bit.

pkgs/development/haskell-modules/generic-builder.nix

@@ -2,42 +2,43 @@
 , jailbreak-cabal, hscolour
 }:
 
-{ pname, version, sha256 ? null
+{ pname
+, version
+, sha256 ? null
 , src ? fetchurl { url = "mirror://hackage/${pname}-${version}.tar.gz"; inherit sha256; }
 , buildDepends ? []
-, extraLibraries ? []
-, configureFlags ? []
-, configureFlagsArray ? []
-, pkgconfigDepends ? []
-, noHaddock ? false
 , buildTools ? []
-, patches ? [], patchPhase ? "", prePatch ? "", postPatch ? ""
+, configureFlags ? []
-, preConfigure ? "", postConfigure ? ""
+, description ? ""
-, preBuild ? "", postBuild ? ""
+, doCheck ? stdenv.lib.versionOlder "7.4" ghc.version
-, installPhase ? "", preInstall ? "", postInstall ? ""
-, checkPhase ? "", preCheck ? "", postCheck ? ""
-, preFixup ? "", postFixup ? ""
-, isExecutable ? false, isLibrary ? !isExecutable
-, propagatedUserEnvPkgs ? []
-, testDepends ? []
-, doCheck ? stdenv.lib.versionOlder "7.4" ghc.version, testTarget ? ""
 , doHoogle ? true
-, jailbreak ? false
+, editedCabalFile ? null
-, hyperlinkSource ? true
 , enableLibraryProfiling ? false
 , enableSharedExecutables ? stdenv.lib.versionOlder "7.7" ghc.version
 , enableSharedLibraries ? stdenv.lib.versionOlder "7.7" ghc.version
 , enableSplitObjs ? !stdenv.isDarwin # http://hackage.haskell.org/trac/ghc/ticket/4013
 , enableStaticLibraries ? true
+, extraLibraries ? []
 , homepage ? "http://hackage.haskell.org/package/${pname}"
-, description ? "no description available"
-, license
-, editedCabalFile ? null
-, platforms ? ghc.meta.platforms
 , hydraPlatforms ? ghc.meta.hydraPlatforms or ghc.meta.platforms
-, broken ? false
+, hyperlinkSource ? true
+, isExecutable ? false, isLibrary ? !isExecutable
+, jailbreak ? false
+, license
 , maintainers ? []
+, noHaddock ? false
 , passthru ? {}
+, pkgconfigDepends ? []
+, platforms ? ghc.meta.platforms
+, testDepends ? []
+, testTarget ? ""
+, broken ? false
+, patches ? [], patchPhase ? "", prePatch ? "", postPatch ? ""
+, preConfigure ? "", postConfigure ? ""
+, preBuild ? "", postBuild ? ""
+, preInstall ? "", postInstall ? ""
+, checkPhase ? "", preCheck ? "", postCheck ? ""
+, preFixup ? "", postFixup ? ""
 }:
 
 assert pkgconfigDepends != [] -> pkgconfig != null;
@@ -45,7 +46,7 @@ assert pkgconfigDepends != [] -> pkgconfig != null;
 let
 
   inherit (stdenv.lib) optional optionals optionalString versionOlder
-                       concatStringsSep enableFeature;
+                       concatStringsSep enableFeature optionalAttrs;
 
   defaultSetupHs = builtins.toFile "Setup.hs" ''
                      import Distribution.Simple
@@ -69,7 +70,7 @@ let
   };
 
 in
-stdenv.mkDerivation {
+stdenv.mkDerivation ({
   name = "${optionalString hasActiveLibrary "haskell-"}${pname}-${version}";
 
   inherit src;
@@ -79,14 +80,6 @@ stdenv.mkDerivation {
     optionals doCheck testDepends;
   propagatedNativeBuildInputs = buildDepends;
 
-  inherit propagatedUserEnvPkgs;
-  inherit patches patchPhase prePatch postPatch;
-  inherit preConfigure postConfigure configureFlags configureFlagsArray;
-  inherit preBuild postBuild;
-  inherit preInstall postInstall;
-  inherit doCheck preCheck postCheck;
-  inherit preFixup postFixup;
-
   # GHC needs the locale configured during the Haddock phase.
   LANG = "en_US.UTF-8";
   LOCALE_ARCHIVE = optionalString stdenv.isLinux "${glibcLocales}/lib/locale/locale-archive";
@@ -111,11 +104,16 @@ stdenv.mkDerivation {
       setupCompileFlags="-j$NIX_BUILD_CORES"
     ''}
 
-    local confDir=$out/nix-support/ghc-${ghc.version}-package.conf.d
+    packageConfDir="$TMP/package.conf.d"
-    mkdir -p $confDir
+    mkdir -p $packageConfDir
-    for p in $propagatedNativeBuildInputs $nativeBuildInputs; do
+
-      if [ -d "$p/nix-support/ghc-${ghc.version}-package.conf.d" ]; then
+    local inputClosure=""
-        cp -f "$p/nix-support/ghc-${ghc.version}-package.conf.d/"*.conf $confDir/
+    for i in $propagatedNativeBuildInputs $nativeBuildInputs; do
+      findInputs $i inputClosure propagated-native-build-inputs
+    done
+    for p in $inputClosure; do
+      if [ -d "$p/lib/${ghc.name}/package.conf.d" ]; then
+        cp -f "$p/lib/${ghc.name}/package.conf.d/"*.conf $packageConfDir/
         continue
       fi
       if [ -d "$p/include" ]; then
@@ -127,8 +125,8 @@ stdenv.mkDerivation {
         fi
       done
     done
-    ghc-pkg --package-db=$confDir recache
+    ghc-pkg --package-db="$packageConfDir" recache
-    configureFlags+=" --package-db=$confDir"
+    configureFlags+=" --package-db=$packageConfDir"
 
     ${optionalString (editedCabalFile != null) ''
       echo "Replacing Cabal file with edited version ${newCabalFile}."
@@ -143,17 +141,17 @@ stdenv.mkDerivation {
     for i in Setup.hs Setup.lhs ${defaultSetupHs}; do
       test -f $i && break
     done
-    ghc -package-db=$confDir $setupCompileFlags --make -o Setup -odir $TMPDIR -hidir $TMPDIR $i
+    ghc -package-db=$packageConfDir $setupCompileFlags --make -o Setup -odir $TMPDIR -hidir $TMPDIR $i
 
     echo configureFlags: $configureFlags
-    unset GHC_PACKAGE_PATH      # Cabal complains about this variable if it's set.
+    unset GHC_PACKAGE_PATH      # Cabal complains if this variable is set during configure.
     ./Setup configure $configureFlags 2>&1 | ${coreutils}/bin/tee "$NIX_BUILD_TOP/cabal-configure.log"
     if ${gnugrep}/bin/egrep -q '^Warning:.*depends on multiple versions' "$NIX_BUILD_TOP/cabal-configure.log"; then
       echo >&2 "*** abort because of serious configure-time warning from Cabal"
       exit 1
     fi
 
-    export GHC_PACKAGE_PATH="$confDir:"
+    export GHC_PACKAGE_PATH="$packageConfDir:"
 
     runHook postConfigure
   '';
@@ -162,29 +160,30 @@ stdenv.mkDerivation {
     runHook preBuild
     ./Setup build
     ${optionalString (!noHaddock && hasActiveLibrary) ''
-      ./Setup haddock --html ${optionalString doHoogle "--hoogle"} ${optionalString (hasActiveLibrary && hyperlinkSource) "--hyperlink-source"}
+      ./Setup haddock --html \
+        ${optionalString doHoogle "--hoogle"} \
+        ${optionalString (hasActiveLibrary && hyperlinkSource) "--hyperlink-source"}
     ''}
     runHook postBuild
   '';
 
-  checkPhase = if installPhase != "" then installPhase else ''
+  checkPhase = ''
     runHook preCheck
     ./Setup test ${testTarget}
     runHook postCheck
   '';
 
-  installPhase = if installPhase != "" then installPhase else ''
+  installPhase = ''
     runHook preInstall
 
     ${if !hasActiveLibrary then "./Setup install" else ''
       ./Setup copy
-      local confDir=$out/nix-support/ghc-${ghc.version}-package.conf.d
+      local packageConfDir="$out/lib/${ghc.name}/package.conf.d"
-      local pkgConf=$confDir/${pname}-${version}.conf
+      local packageConfFile="$packageConfDir/${pname}-${version}.conf"
-      mkdir -p $confDir
+      mkdir -p "$packageConfDir"
-      ./Setup register --gen-pkg-config=$pkgConf
+      ./Setup register --gen-pkg-config=$packageConfFile
-      local pkgId=$( ${gnused}/bin/sed -n -e 's|^id: ||p' $pkgConf )
+      local pkgId=$( ${gnused}/bin/sed -n -e 's|^id: ||p' $packageConfFile )
-      mv $pkgConf $confDir/$pkgId.conf
+      mv $packageConfFile $packageConfDir/$pkgId.conf
-      ghc-pkg --package-db=$confDir recache
     ''}
 
     ${optionalString (enableSharedExecutables && isExecutable && stdenv.isDarwin) ''
@@ -198,7 +197,27 @@ stdenv.mkDerivation {
 
   passthru = passthru // { inherit pname version; };
 
-  meta = {
+  meta = { inherit homepage license platforms hydraPlatforms; }
-    inherit homepage license description platforms hydraPlatforms maintainers broken;
+         // optionalAttrs broken               { inherit broken; }
-  };
+         // optionalAttrs (description != "")  { inherit description; }
+         // optionalAttrs (maintainers != [])  { inherit maintainers; }
+         ;
+
 }
+// optionalAttrs (configureFlags != []) { inherit configureFlags; }
+// optionalAttrs (patches != [])        { inherit patches; }
+// optionalAttrs (patchPhase != "")     { inherit patchPhase; }
+// optionalAttrs (prePatch != "")       { inherit prePatch; }
+// optionalAttrs (postPatch != "")      { inherit postPatch; }
+// optionalAttrs (preConfigure != "")   { inherit preConfigure; }
+// optionalAttrs (postConfigure != "")  { inherit postConfigure; }
+// optionalAttrs (preBuild != "")       { inherit preBuild; }
+// optionalAttrs (postBuild != "")      { inherit postBuild; }
+// optionalAttrs (preInstall != "")     { inherit preInstall; }
+// optionalAttrs (postInstall != "")    { inherit postInstall; }
+// optionalAttrs (checkPhase != "")     { inherit checkPhase; }
+// optionalAttrs (preCheck != "")       { inherit preCheck; }
+// optionalAttrs (postCheck != "")      { inherit postCheck; }
+// optionalAttrs (preFixup != "")       { inherit preFixup; }
+// optionalAttrs (postFixup != "")      { inherit postFixup; }
+)

pkgs/development/haskell-modules/with-packages-wrapper.nix

@@ -31,11 +31,12 @@ let
   docDir        = "$out/share/doc/ghc/html";
   packageCfgDir = "${libDir}/package.conf.d";
   isHaskellPkg  = x: (x ? pname) && (x ? version);
+  paths         = stdenv.lib.filter isHaskellPkg (stdenv.lib.closePropagation packages);
 in
-if packages == [] then ghc else
+if paths == [] then ghc else
-stdenv.lib.addPassthru (buildEnv {
+buildEnv {
   inherit (ghc) name;
-  paths = stdenv.lib.filter isHaskellPkg (stdenv.lib.closePropagation packages) ++ [ghc];
+  paths = paths ++ [ghc];
   inherit ignoreCollisions;
   postBuild = ''
     . ${makeWrapper}/nix-support/setup-hook
@@ -72,15 +73,10 @@ stdenv.lib.addPassthru (buildEnv {
       makeWrapper ${ghc}/bin/$prg $out/bin/$prg --add-flags "${packageDBFlag}=${packageCfgDir}"
     done
 
-    rm $out/lib/${ghc.name}/package.conf.d
-    mkdir $out/lib/${ghc.name}/package.conf.d
-    for pkg in $paths; do
-      for file in "$pkg/nix-support/${ghc.name}-package.conf.d/"*.conf "$pkg/lib/${ghc.name}/package.conf.d/"*.conf; do
-        ln -sf $file $out/lib/${ghc.name}/package.conf.d/
-      done
-    done
-
     $out/bin/ghc-pkg recache
     $out/bin/ghc-pkg check
   '';
-}) { inherit (ghc) version; }
+} // {
+  preferLocalBuild = true;
+  inherit (ghc) version meta;
+}