update my_env. Hopefully does a better job now

svn path=/nixpkgs/trunk/; revision=13037

pkgs/misc/my-env/default.nix

@@ -0,0 +1,79 @@
+# idea: provide nix environment for your developement actions
+# experimental
+
+/*
+  # example:
+  # add postgresql to environment and create ctags (tagfiles can be extracted from TAG_FILES)
+  # add this to your ~/.nixpkgs/config.nix
+
+  {
+    packageOverrides = pkgs : with pkgs; with sourceAndTags;
+    let simple = { name, buildInputs ? [], cTags ? [], extraCmds ? ""}:
+            pkgs.myEnvFun {
+              inherit name;
+            buildInputs = buildInputs 
+                  ++ map (x : sourceWithTagsDerivation ( (addCTaggingInfo x ).passthru.sourceWithTags ) ) cTags;
+            extraCmds = ''
+              ${extraCmds}
+              HOME=${builtins.getEnv "HOME"}
+              . ~/.bashrc
+            '';
+          };
+    in rec {
+      nixEnv = simple {
+       name = "nix";
+       buildInputs = [ libtool stdenv perl curl bzip2 openssl aterm242fixes db45 autoconf automake zlib ];
+       cTags = [ aterm242fixes];
+      };
+      [...]
+    };
+  }
+
+
+  Put this into your .bashrc
+    loadEnv(){ . "${HOME}/.nix-profile/dev-envs/${1}" }
+
+  then nix-env -iA ...nixEnv
+  and
+  $ loadEnv postgresql
+
+*/
+
+{ mkDerivation, substituteAll, pkgs } : { stdenv ? pkgs.stdenv, name, buildInputs ? [], cTags ? [], extraCmds ? ""} :
+mkDerivation {
+  buildInputs = [ ] ++ buildInputs ;
+  name = "env-${name}";
+  phases = "buildPhase";
+  setupNew = substituteAll {
+    src = ../../stdenv/generic/setup-new.sh;
+    preHook="";
+    postHook="";
+    initialPath= (import ../../stdenv/common-path.nix) { inherit pkgs; };
+    gcc = stdenv.gcc;
+  };
+  buildPhase = ''
+    set -x
+    mkdir -p "$out/dev-envs" "$out/nix-support"
+    s="$out/nix-support/setup-new-modified"
+    cp "$setupNew" "$s"
+    # shut some warning up.., do not use set -e
+    sed -e 's@set -e@@' \
+        -e 's@assertEnvExists\s\+NIX_STORE@:@' \
+        -e 's@trap.*@@' \
+        -i "$s"
+    cat >> "$out/dev-envs/''${name/env-/}" << EOF
+      buildInputs="$buildInputs"
+      # the setup-new script wants to write some data to a temp file.. so just let it do that and tidy up afterwards
+      tmp="\$("${pkgs.coreutils}/bin/mktemp" -d)"
+      NIX_BUILD_TOP="\$tmp"
+      phases=
+      # only do all the setup stuff in nix-support/*
+      set +e
+      source "$s"
+      rm -fr "\$tmp"
+      ${extraCmds}
+      export PATH
+      echo $name loaded
+    EOF
+  '';
+}

pkgs/misc/my_env/default.nix

@@ -1,58 +0,0 @@
-# idea: provide nix environment for your developement actions
-# experimental
-
-/*
-  # example: 
-  # add postgresql to environment and create ctags (tagfiles can be extracted from TAG_FILES)
-  # add this to your ~/.nixpkgs/config.nix
-
- devEnvs = pkgs : with pkgs; with sourceAndTags;
-  let simple = { name, buildInputs ? [], cTags ? [] }:
-          pkgs.myEnvFun {
-            inherit name stdenv;
-          buildInputs = buildInputs 
-                ++ map (x : sourceWithTagsDerivation ( (addCTaggingInfo x ).passthru.sourceWithTags ) ) cTags;
-          extraCmds = ". ~/.bashrc; cd $PWD
-            # configure should find them
-            export LDFLAGS=$NIX_LDFLAGS
-            export CFLAGS=$NIX_CFLAGS_COMPILE
-            ";
-          preBuild = "export TAG_FILES";
-        };
-  in {
-    postgresql = simple {
-     name = "postgresql";
-     buildInputs = [postgresql];
-     cTags = [postgresql ];
-    };
-  };
-
-  Put this into your .bashrc
-    loadEnv(){ . "${HOME}/.nix-profile/dev-envs/${1}" }
-  then install and 
-    $ loadEnv postgresql
-
-*/
-
-args: args.stdenv.mkDerivation ( 
-  { extraCmds =""; } // {
-  phases = "buildPhase";
-  buildPhase = '' 
-    eval "$preBuild"
-    name=${args.name}
-    o=$out/dev-envs/$name
-    ensureDir `dirname $o`
-    echo "
-    OLDPATH=\$PATH " >> $o
-    export | grep -v HOME= | grep -v PATH= | grep -v PWD= | grep -v TEMP= | grep -v TMP= >> $o 
-    echo "
-    PATH=$PATH:$OLDPATH
-    for i in \$buildInputs; do
-      export LD_LIBRARY_PATH=\$LD_LIBRARY_PATH:\$i/lib
-    done
-    export PATH=\$PATH:\$OLDPATH
-    $extraCmds
-    echo env $name loaded
-    " >> $o
-  '';
-} // args // { name = "${args.name}-env"; } )

pkgs/top-level/all-packages.nix

@@ -7746,6 +7746,9 @@ let
     inherit (xlibs) libX11;
   };
 
-  myEnvFun = import ../misc/my_env;
+  myEnvFun = import ../misc/my-env {
+    inherit substituteAll pkgs;
+    inherit (stdenv) mkDerivation;
+  };
 
 }; in pkgs