pkgs/development/compilers/ghc/with-packages.nix: simply this wrapper on top of buildenv

pkgs/development/compilers/ghc/with-packages.nix

···
-{stdenv, ghc, packages ? [], makeWrapper}:
-
-stdenv.mkDerivation rec {
-  name = "haskell-env-${ghc.name}";
-
-  allPackages = stdenv.lib.closePropagation packages;
-  buildInputs = allPackages ++ [makeWrapper];
-  propagatedBuildInputs = packages;
-
-  unpackPhase = "true";
-
-  installPhase = ''
-    numversion=$(${ghc}/bin/ghc --numeric-version)
-    majorversion=''${numversion%%.*}
-    minorversion=''${numversion#*.}
-    minorversion=''${minorversion%%.*}
-
-    if [[ $majorversion -gt 6 ]] && [[ $minorversion -gt 4 ]]; then
-      globalConf="--global-package-db"
-    else
-      globalConf="--global-conf"
-    fi
-
-    originalTopDir="${ghc}/lib/ghc-${ghc.version}"
-    originalPkgDir="$originalTopDir/package.conf.d"
-    linkedTopDir="$out/lib"
-    linkedPkgDir="$linkedTopDir/package.conf.d"
-
-    mkdir -p $out/bin
-    mkdir -p $linkedTopDir
-    mkdir -p $linkedPkgDir
-
-    echo "Linking GHC core libraries:"
-
-    echo -n "Linking $originalTopDir "
-    for f in "$originalTopDir/"*; do
-      if test -f $f; then
-        ln -s $f $linkedTopDir
-        echo -n .
-      fi
-    done
-    echo
-
-    echo -n "Linking $originalPkgDir "
-    for f in "$originalPkgDir/"*.conf; do
-      ln -s $f $linkedPkgDir
-      echo -n .
-    done
-    echo
-
-    echo "Linking selected packages and dependencies:"
-
-    for currentPath in ${stdenv.lib.concatStringsSep " " allPackages}; do
-      currentPkgDir="$currentPath/lib/ghc-${ghc.version}/package.conf.d/"
-      # Check if current path is a Cabal package for the current GHC
-      if test -d $currentPkgDir; then
-        echo -n "Linking $currentPath "
-        for f in "$currentPath/bin/"*; do
-          ln -s $f $out/bin
-          echo -n .
-        done
-        for f in "$currentPath/etc/bash_completion.d/"*; do
-          mkdir -p $out/etc/bash_completion.d
-          ln -s $f $out/etc/bash_completion.d/
-          echo -n .
-        done
-        for s in 1 2 3 4 5 6 7 8 9; do
-          for f in "$currentPath/share/man/man$s/"*; do
-            mkdir -p $out/share/man/man$s
-            ln -sv $f $out/share/man/man$s/
-            echo -n .
-          done
-        done
-        for f in "$currentPath/share/emacs/site-lisp/"*; do
-          mkdir -p $out/share/emacs/site-lisp
-          ln -s $f $out/share/emacs/site-lisp/
-          echo -n .
-        done
-        for f in "$currentPkgDir/"*.conf; do
-          ln -s $f $linkedPkgDir
-          echo -n .
-        done
-        echo
-      fi
-    done
+{ stdenv, ghc, packages, buildEnv, makeWrapper }:
 
-    echo -n "Generating package cache "
-    ${ghc}/bin/ghc-pkg $globalConf $linkedPkgDir recache
-    echo .
+assert packages != [];
 
-    echo -n "Generating wrappers "
+let
+  ghc761OrLater = stdenv.lib.versionOlder "7.6.1" ghc.version;
+  packageDBFlag = if ghc761OrLater then "--package-db" else "--package-conf";
+  libDir        = "$out/lib/ghc-${ghc.version}";
+  packageCfgDir = "${libDir}/package.conf.d";
+in
+buildEnv {
+  name = "haskell-env-${ghc.name}";
+  paths = stdenv.lib.closePropagation (packages ++ [ghc]);
+  postBuild = ''
+    . ${makeWrapper}/nix-support/setup-hook
 
     for prg in ghc ghci ghc-${ghc.version} ghci-${ghc.version}; do
-      # The NIX env-vars are picked up by our patched version of ghc-paths.
-      makeWrapper ${ghc}/bin/$prg $out/bin/$prg \
-        --add-flags "-B$linkedTopDir" \
-        --set "NIX_GHC"        "$out/bin/ghc"     \
-        --set "NIX_GHCPKG"     "$out/bin/ghc-pkg" \
-        --set "NIX_GHC_LIBDIR" "$linkedTopDir"
-      echo -n .
+      rm -f $out/bin/$prg
+      makeWrapper ${ghc}/bin/$prg $out/bin/$prg         \
+        --add-flags '"-B$NIX_GHC_LIBDIR"'               \
+        --set "NIX_GHC"        "$out/bin/ghc"           \
+        --set "NIX_GHCPKG"     "$out/bin/ghc-pkg"       \
+        --set "NIX_GHC_LIBDIR" "${libDir}"
     done
 
     for prg in runghc runhaskell; do
+      rm -f $out/bin/$prg
       makeWrapper ${ghc}/bin/$prg $out/bin/$prg --add-flags "-f $out/bin/ghc"
-      echo -n .
     done
 
     for prg in ghc-pkg ghc-pkg-${ghc.version}; do
-      makeWrapper ${ghc}/bin/$prg $out/bin/$prg --add-flags "$globalConf $linkedPkgDir"
-      echo -n .
+      rm -f $out/bin/$prg
+      makeWrapper ${ghc}/bin/$prg $out/bin/$prg --add-flags "${packageDBFlag} ${packageCfgDir}"
     done
 
-    for prg in hp2ps hpc hasktags hsc2hs haddock haddock-${ghc.version}; do
-      if test -x ${ghc}/bin/$prg -a ! -x $out/bin/$prg; then
-        ln -s ${ghc}/bin/$prg $out/bin/$prg && echo -n .
-      fi
-    done
-    echo
+    $out/bin/ghc-pkg recache
   '';
-
-  meta = ghc.meta;
 }