diff --git a/pkgs/applications/audio/picard/default.nix b/pkgs/applications/audio/picard/default.nix
index 5830e1eefb88c..0c612338361f4 100644
--- a/pkgs/applications/audio/picard/default.nix
+++ b/pkgs/applications/audio/picard/default.nix
@@ -21,7 +21,15 @@ in pythonPackages.buildPythonApplication rec {
     sha256 = "0xalg4dvaqb396h4s6gzxnplgv1lcvsczmmrlhyrj0kfj10amhsj";
   };
 
-  nativeBuildInputs = [ gettext qt5.wrapQtAppsHook qt5.qtbase ]
+  nativeBuildInputs = [ gettext qt5.wrapQtAppsHook ];
+
+  propagatedBuildInputs = with pythonPackages; [
+    qt5.qtbase
+    pyqt5
+    mutagen
+    chromaprint
+    discid
+  ]
     ++ stdenv.lib.optionals (pyqt5.multimediaEnabled) [
       qt5.qtmultimedia.bin
       gst_all_1.gstreamer
@@ -32,18 +40,12 @@ in pythonPackages.buildPythonApplication rec {
     ]
   ;
 
-  propagatedBuildInputs = with pythonPackages; [
-    pyqt5
-    mutagen
-    chromaprint
-    discid
-  ];
-
   prePatch = ''
     # Pesky unicode punctuation.
     substituteInPlace setup.cfg --replace "‘" "'"
   '';
 
+  dontWrapPythonPrograms = (qt5.wrapQtAppsHook == null);
   # In order to spare double wrapping, we use:
   preFixup = ''
     makeWrapperArgs+=("''${qtWrapperArgs[@]}")
diff --git a/pkgs/build-support/neowrap.nix b/pkgs/build-support/neowrap.nix
new file mode 100644
index 0000000000000..88b954779bba8
--- /dev/null
+++ b/pkgs/build-support/neowrap.nix
@@ -0,0 +1,294 @@
+{ lib
+, symlinkJoin
+, makeWrapper
+, lndir
+, pkgs
+, extraPkgsByOverride ? []
+}:
+
+# A single pkg or a list of pkgs mainly packaged
+pkgList:
+
+let
+  wrapper = {
+    extraPkgs ? [],
+    extraMakeWrapperArgs ? "",
+    # An attribute set that tells the builder how to handle links per file /
+    # directory found in every key of propagateEnv. E.g:
+    /*** example value ***
+    linkByEnv = {
+      # Tells the builder to link the files in every directory that propagates
+      # XDG_DATA_DIRS.
+      XDG_DATA_DIRS = "link";
+      # Tells the builder to simply link all the files of a package that
+      # propagets this env var. Note that this may affect closure size of the
+      # result as every pkg's all outputs are used unconditionally. Useful for
+      # python / other languages wrappings
+      GI_TYPELIB_PATH = "linkPkg";
+    },
+    /*** Another example value ***
+    linkByEnv ? {
+      QT_PLUGIN_PATH = "link";
+      QML2_IMPORT_PATH = "link";
+    },
+    */
+    # TODO: Decide what to do when `linkPkg` is used here and the file
+    # nix-support/propagated-build-inputs has different values per package
+    linkByEnv ? {},
+    # If we want the wrapping to also include an environmental variable in
+    # out, we list here for every env var what path to add to the wrapper's
+    # values.
+    /*** example value ***
+    wrapOut ? {
+      XDG_DATA_DIRS = "$out/share";
+      PYTHONPATH = "$out/${pkgs.python3.sitePackages}";
+    },
+    */
+    wrapOut ? {},
+  }:
+  let
+    # Where we keep general knowledge about known to be used environmental variables
+    encyclopedia = {
+      # Here we write the separator string between values of every env var, the
+      # default is ":"
+      separators = {
+        # XDG_DATA_DIRS = ":";
+      };
+      # If the `link` argument was supplied, we use the keys provided here as a
+      # dictionary that defines where to symlink the files that the caller
+      # wants to be symlinked as well, per env var. If a key shows up here and
+      # in wrapOut as well, it is expected they will have the same value.
+      linkPaths = {
+        XDG_DATA_DIRS = "$out/share";
+        GI_TYPELIB_PATH = "$out/lib/girepository-1.0";
+        QT_PLUGIN_PATH = "$out/${pkgs.qt5.qtbase.qtPluginPrefix}";
+        QML2_IMPORT_PATH = "$out/${pkgs.qt5.qtbase.qtQmlPrefix}";
+        # Not using a strict version here as it may confuse someone digging
+        # into the results of this wrapper
+        PYTHONPATH = "$out/python-sitePackages";
+      };
+      # If you want an environment variable to have a single value and that's it,
+      # put it here:
+      singleValue = [
+        "GDK_PIXBUF_MODULE_FILE"
+      ];
+      # To prevent a stack overflow when inspecting a derivation's inputs
+      # recursively, we use this list to tell the function that dives into the
+      # dependency graph, what packages should be skipped instantly.
+      skipDivingInto = with pkgs; [
+        gnu-efi iptables kexectools libapparmor libcap libidn2 libmicrohttpd
+        libnetfilter_conntrack libnftnl libseccomp pciutils systemd acl autogen
+        gnutls guile libevent p11-kit unbound xorg.libXext freetype xorg.libICE
+        libpng_apng kmod libgcrypt curl libkrb5 libssh2 nghttp2 libtool nettle
+        glib libselinux utillinux xorg.libX11 xorg.libxcb xorg.libXdmcp libxslt cracklib
+        linux-pam xorg.libXau libxml2 sqlite readline bison zlib libffi openssl ncurses
+        # Note we add perl itself here, not any library of it
+        perl xorg.xorgproto expat xz fontconfig xorg.libXfixes llvm
+      ];
+    };
+    # recursive function that goes deep through the dependency graph of a given
+    # list of packages and creates a list of all buildInputs they all depend
+    # on. The 2nd argument pkgsFound is used internally and it's expected to be
+    # [] at the first call.
+    getAllInputs =
+      pkgs:
+      pkgsFound:
+      map (
+        pkg:
+        if builtins.isAttrs pkg then
+          let
+            inEncyclopedia =
+              inputPkg:
+              lib.lists.any (
+                knownPkg:
+                if builtins.isAttrs inputPkg then
+                  # builtins.trace "testing ${inputPkg.name} if in encyclopedia: ${builtins.toJSON (inputPkg.name == knownPkg.name)}" inputPkg.name == knownPkg.name
+                  inputPkg.name == knownPkg.name
+                else
+                  false
+                ) encyclopedia.skipDivingInto
+            ;
+            notInEncyclopedia = 
+              inputPkg:
+              !(inEncyclopedia inputPkg)
+            ;
+            hasInputs = pkg.buildInputs != [] || pkg.propagatedBuildInputs != [];
+          in
+            if !(inEncyclopedia pkg) && hasInputs then
+              let
+                # From some reason, pkg == knownPkg doesn't work :/ don't know
+                # why... Never the less this should be good enough
+                deeperPkgs = builtins.filter notInEncyclopedia (pkg.buildInputs ++ pkg.propagatedBuildInputs);
+                deeperPkgs_ = builtins.trace "deeper is ${builtins.toJSON deeperPkgs}" deeperPkgs;
+                currentPkgs = pkgsFound ++ pkgs;
+              in
+                (getAllInputs deeperPkgs currentPkgs)
+            else
+              pkgsFound ++ [ pkg ]
+        else
+          []
+      ) pkgs
+    ;
+    allPkgs = (lib.lists.flatten pkgList) ++ extraPkgsByOverride ++ extraPkgs;
+    # Useful for debugging, not evaluated if not used.
+    allPkgs_ = builtins.trace "allPkgs is: ${builtins.toJSON allPkgs}" allPkgs;
+    allInputs = lib.lists.unique (lib.lists.flatten (getAllInputs allPkgs []));
+    # Useful for debugging, not evaluated if not used.
+    allInputs_ = builtins.trace "allInputs is: ${builtins.toJSON allInputs}" allInputs;
+    # filter out of all the inputs the packages with the propagateEnv attribute
+    envPkgs = builtins.filter (
+      pkg:
+      if builtins.isAttrs pkg then
+        (builtins.hasAttr "propagateEnv" pkg)
+      else
+        false
+    ) allInputs;
+    # Useful for debugging, not evaluated if not used.
+    envPkgs_ = builtins.trace "envPkgs is: ${builtins.toJSON envPkgs}" envPkgs;
+    # Given a package, it's outputs and an envStr such as found in the values
+    # of passthru's `propagateEnv`, it replaces all occurences of %<outname>%
+    # from envStr according to the pkg.outputs
+    replaceAllOutputs = {
+      pkg,
+      envStr,
+      outputs,
+      outname ? "out",
+    }:
+      let
+        outname = builtins.elemAt outputs 0;
+      in
+      if (builtins.length outputs) == 0 then
+        envStr
+      else
+        replaceAllOutputs {
+          inherit pkg;
+          outputs = lib.lists.subtractLists [outname] outputs;
+          envStr = builtins.replaceStrings
+            [ "@${outname}@" ]
+            [ "${pkg.${outname}}" ]
+          envStr;
+        }
+    ;
+    # Where we calculate every env var's values. This also considers the `link`
+    # argument's value - if it was requested to `link` directories of certain
+    # env vars or paths, that's taken care of later, at `linkInfo`. The
+    # encyclopedia's `linkPaths` set is used if needed.
+    envInfo = lib.attrsets.foldAttrs (n: a: lib.lists.unique ([n] ++ a)) [] (map (
+      pkg:
+      # for every package in envPkgs, do the following for every env key and value
+      (lib.attrsets.mapAttrs (
+        # env var name
+        name:
+        # env var value
+        value:
+        let
+          real_value = replaceAllOutputs {
+            inherit pkg;
+            outputs = pkg.outputs;
+            envStr = value;
+          };
+        in
+          if builtins.hasAttr name linkByEnv then
+            if linkByEnv.${name} == "link" then
+              if builtins.hasAttr name encyclopedia.linkPaths then
+                {
+                  linkType = "normal";
+                  linkTo = encyclopedia.linkPaths.${name};
+                  linkFrom = real_value;
+                }
+              else 
+                abort "neowrap.nix: I was requested to symlink paths of propagated environment for env var `${name}` but I don't know where to put these files as they are not in my encyclopedia"
+            else
+              if linkByEnv.${name} != "linkPkg" then
+                abort "neowrap.nix: got an unknown value for a linkByenv env key: ${name}"
+              else
+                {
+                  linkType = "pkg";
+                  linkTo = "$out";
+                  # Should this be `pkg.dev` or simply `pkg` ?
+                  linkFrom = pkg.out;
+                }
+          else
+            real_value
+      ) pkg.propagateEnv)
+    ) envPkgs);
+    # Useful for debugging, not evaluated if not used.
+    envInfo_ = builtins.trace "envInfo is ${(builtins.toJSON envInfo)}" envInfo;
+    makeWrapperArgs = lib.lists.flatten (lib.attrsets.mapAttrsToList (
+      key:
+      value:
+      (let
+        sep = encyclopedia.separators.${key} or ":"; # default separator used for most wrappings
+      in
+        # To filter out envInfo changed via the `linkByEnv` argument
+        if builtins.isString (builtins.elemAt value 0) then
+          if builtins.elem key encyclopedia.singleValue then
+            if (builtins.length value) > 1 then
+              abort "neowrap.nix: There is more then 1 derivation in all inputs of: ${builtins.toJSON allPkgs} that set ${key} to a value via a passthru. This env key, is defined in my encyclopedia as a single value key. Hence I don't know what value to use in wrapping."
+            else
+              # Should this be "--set" ?
+              "--set-default ${key} ${builtins.elemAt value 0}"
+          else
+            "--prefix ${key} ${sep} ${builtins.concatStringsSep sep value}"
+        else
+          # duplicates are removed by lib.lists.flatten at the beginning
+          if (builtins.elemAt value 0).linkType == "normal" then
+            "--prefix ${key} ${sep} ${(builtins.elemAt value 0).linkTo}"
+          else # (builtins.elemAt value 0).linkType == "pkg" then
+            if builtins.hasAttr key wrapOut || builtins.hasAttr key encyclopedia.linkPaths then
+              "--prefix ${key} ${sep} ${wrapOut.${key} or encyclopedia.linkPaths.${key}}"
+            else
+              abort "neowrap.nix: When requested to link packages of env var ${key}, I couldn't decide where to link them _to_, either set wrapOut.${key} to e.g $out/${key}, and that directory will be added to the values of ${key}, or add an entry to the encyclopedia.linkPaths attribute set"
+      )
+    )
+      # Before calculating makeWrapperArgs, we need to add values to env vars
+      # according to the `wrapOut` argument:
+      (lib.attrsets.mapAttrs (
+        name:
+        values:
+        if builtins.hasAttr name wrapOut && builtins.isList values then
+          if builtins.elem wrapOut.${name} values then
+            values
+          else
+            values ++ [wrapOut.${name}]
+        else
+          values
+      ) envInfo)
+    );
+    makeWrapperArgs_ = builtins.trace "makeWrapperArgs is ${builtins.toJSON makeWrapperArgs}" makeWrapperArgs;
+    linkCmds = lib.lists.flatten (lib.attrsets.mapAttrsToList (
+      key:
+      values:
+      (let
+        sep = encyclopedia.separators.${key} or ":"; # default separator used for most wrappings
+      in
+        if builtins.isAttrs (builtins.elemAt values 0) then
+          (map (
+            v:
+            "mkdir -p ${v.linkTo} && lndir -silent ${v.linkFrom} ${v.linkTo}"
+          ) values)
+        else
+          # removed by lib.lists.flatten at the beginning
+          []
+      )
+    )
+      envInfo
+    );
+    # Useful for debugging, not evaluated if not used.
+    linkCmds_ = builtins.trace "linkCmds is ${builtins.toJSON linkCmds}" linkCmds;
+  in
+  symlinkJoin {
+    name = "runtime-env";
+    paths = pkgList;
+    passthru.unwrapped = pkgList;
+
+    buildInputs = [ makeWrapper lndir ];
+    postBuild = ''
+      ${builtins.concatStringsSep "\n" linkCmds}
+      for i in $out/bin/*; do
+        wrapProgram "$i" ${builtins.concatStringsSep " " makeWrapperArgs}
+      done
+    '';
+  };
+in
+  lib.makeOverridable wrapper
diff --git a/pkgs/development/libraries/atk/default.nix b/pkgs/development/libraries/atk/default.nix
index 400ddd5125953..bbbd4f6a8cc3e 100644
--- a/pkgs/development/libraries/atk/default.nix
+++ b/pkgs/development/libraries/atk/default.nix
@@ -38,6 +38,9 @@ stdenv.mkDerivation rec {
     updateScript = gnome3.updateScript {
       packageName = pname;
     };
+    propagateEnv = {
+      GI_TYPELIB_PATH = "@out@/lib/girepository-1.0";
+    };
   };
 
   meta = {
diff --git a/pkgs/development/libraries/dconf/default.nix b/pkgs/development/libraries/dconf/default.nix
index 8c3a2965484f3..9f4926fa41397 100644
--- a/pkgs/development/libraries/dconf/default.nix
+++ b/pkgs/development/libraries/dconf/default.nix
@@ -35,6 +35,9 @@ stdenv.mkDerivation rec {
     updateScript = gnome3.updateScript {
       packageName = pname;
     };
+    propagateEnv = {
+      GIO_EXTRA_MODULES = "@lib@/lib/gio/modules";
+    };
   };
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/libraries/gdk-pixbuf/default.nix b/pkgs/development/libraries/gdk-pixbuf/default.nix
index b45b578eac0e4..3d297fc9d505c 100644
--- a/pkgs/development/libraries/gdk-pixbuf/default.nix
+++ b/pkgs/development/libraries/gdk-pixbuf/default.nix
@@ -98,6 +98,10 @@ in stdenv.mkDerivation rec {
 
     # gdk_pixbuf_moduledir variable from gdk-pixbuf-2.0.pc
     moduleDir = "lib/gdk-pixbuf-2.0/2.10.0/loaders";
+    cacheFile = "lib/gdk-pixbuf-2.0/2.10.0/loaders.cache";
+    propagateEnv = {
+      GI_TYPELIB_PATH = "@out@/lib/girepository-1.0";
+    };
   };
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/libraries/gobject-introspection/default.nix b/pkgs/development/libraries/gobject-introspection/default.nix
index b9303bd5731eb..8156e1a765bdf 100644
--- a/pkgs/development/libraries/gobject-introspection/default.nix
+++ b/pkgs/development/libraries/gobject-introspection/default.nix
@@ -72,6 +72,9 @@ stdenv.mkDerivation rec {
     updateScript = gnome3.updateScript {
       packageName = pname;
     };
+    propagateEnv = {
+      GI_TYPELIB_PATH = "@out@/lib/girepository-1.0";
+    };
   };
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/libraries/gsettings-desktop-schemas/default.nix b/pkgs/development/libraries/gsettings-desktop-schemas/default.nix
index a23027946a491..b6aee0f4c1030 100644
--- a/pkgs/development/libraries/gsettings-desktop-schemas/default.nix
+++ b/pkgs/development/libraries/gsettings-desktop-schemas/default.nix
@@ -16,6 +16,10 @@ stdenv.mkDerivation rec {
 
   passthru = {
     updateScript = gnome3.updateScript { packageName = "gsettings-desktop-schemas"; };
+    propagateEnv = {
+      XDG_DATA_DIRS = "@out@/share/gsettings-schemas/${pname}-${version}";
+      GI_TYPELIB_PATH = "@out@/lib/girepository-1.0";
+    };
   };
 
   # meson installs the schemas to share/glib-2.0/schemas
diff --git a/pkgs/development/libraries/gstreamer/bad/default.nix b/pkgs/development/libraries/gstreamer/bad/default.nix
index ae5fd7531325f..a43ec17c2b8c9 100644
--- a/pkgs/development/libraries/gstreamer/bad/default.nix
+++ b/pkgs/development/libraries/gstreamer/bad/default.nix
@@ -278,6 +278,12 @@ in stdenv.mkDerivation rec {
   # that trip up clang with format security enabled.
   hardeningDisable = [ "format" ];
 
+  passthru = {
+    propagateEnv = {
+      GST_PLUGIN_SYSTEM_PATH_1_0 = "@out@/lib/gstreamer-1.0";
+    };
+  };
+
   doCheck = false; # fails 20 out of 58 tests, expensive
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/libraries/gstreamer/base/default.nix b/pkgs/development/libraries/gstreamer/base/default.nix
index 79405e5077e03..02cbe7326f3d1 100644
--- a/pkgs/development/libraries/gstreamer/base/default.nix
+++ b/pkgs/development/libraries/gstreamer/base/default.nix
@@ -135,6 +135,9 @@ stdenv.mkDerivation rec {
   doCheck = false; # fails, wants DRI access for OpenGL
 
   passthru = {
+    propagateEnv = {
+      GST_PLUGIN_SYSTEM_PATH_1_0 = "@out@/lib/gstreamer-1.0";
+    };
     # Downstream `gst-*` packages depending on `gst-plugins-base`
     # have meson build options like 'gl' etc. that depend
     # on these features being built in `-base`.
diff --git a/pkgs/development/libraries/gstreamer/core/default.nix b/pkgs/development/libraries/gstreamer/core/default.nix
index 67a0aa9f3f890..b49f0f8e5956e 100644
--- a/pkgs/development/libraries/gstreamer/core/default.nix
+++ b/pkgs/development/libraries/gstreamer/core/default.nix
@@ -100,6 +100,12 @@ stdenv.mkDerivation rec {
     moveToOutput "share/bash-completion" "$dev"
   '';
 
+  passthru = {
+    propagateEnv = {
+      GST_PLUGIN_SYSTEM_PATH_1_0 = "@out@/lib/gstreamer-1.0";
+    };
+  };
+
   setupHook = ./setup-hook.sh;
 
   meta = with lib ;{
diff --git a/pkgs/development/libraries/gstreamer/ges/default.nix b/pkgs/development/libraries/gstreamer/ges/default.nix
index af2579d0594bb..2c2c7495c50c2 100644
--- a/pkgs/development/libraries/gstreamer/ges/default.nix
+++ b/pkgs/development/libraries/gstreamer/ges/default.nix
@@ -55,6 +55,12 @@ stdenv.mkDerivation rec {
     sed -i -r -e 's/p(bad|good) = .*/p\1 = pbase/' tests/check/meson.build
   '';
 
+  passthru = {
+    propagateEnv = {
+      GST_PLUGIN_SYSTEM_PATH_1_0 = "@out@/lib/gstreamer-1.0";
+    };
+  };
+
   meta = with stdenv.lib; {
     description = "Library for creation of audio/video non-linear editors";
     homepage = "https://gstreamer.freedesktop.org";
diff --git a/pkgs/development/libraries/gstreamer/good/default.nix b/pkgs/development/libraries/gstreamer/good/default.nix
index a7c2bcf838e7b..8ef2abf21156e 100644
--- a/pkgs/development/libraries/gstreamer/good/default.nix
+++ b/pkgs/development/libraries/gstreamer/good/default.nix
@@ -136,6 +136,12 @@ stdenv.mkDerivation rec {
   # fails 1 tests with "Unexpected critical/warning: g_object_set_is_valid_property: object class 'GstRtpStorage' has no property named ''"
   doCheck = false;
 
+  passthru = {
+    propagateEnv = {
+      GST_PLUGIN_SYSTEM_PATH_1_0 = "@out@/lib/gstreamer-1.0";
+    };
+  };
+
   meta = with stdenv.lib; {
     description = "GStreamer Good Plugins";
     homepage = "https://gstreamer.freedesktop.org";
diff --git a/pkgs/development/libraries/gstreamer/libav/default.nix b/pkgs/development/libraries/gstreamer/libav/default.nix
index e36eba3700712..b800ac6c321ab 100644
--- a/pkgs/development/libraries/gstreamer/libav/default.nix
+++ b/pkgs/development/libraries/gstreamer/libav/default.nix
@@ -37,6 +37,12 @@ stdenv.mkDerivation rec {
     libav
   ];
 
+  passthru = {
+    propagateEnv = {
+      GST_PLUGIN_SYSTEM_PATH_1_0 = "@out@/lib/gstreamer-1.0";
+    };
+  };
+
   meta = with lib; {
     description = "FFmpeg/libav plugin for GStreamer";
     homepage = "https://gstreamer.freedesktop.org";
diff --git a/pkgs/development/libraries/gstreamer/ugly/default.nix b/pkgs/development/libraries/gstreamer/ugly/default.nix
index d8c36fa40705c..2c4ab2615c32f 100644
--- a/pkgs/development/libraries/gstreamer/ugly/default.nix
+++ b/pkgs/development/libraries/gstreamer/ugly/default.nix
@@ -55,6 +55,12 @@ stdenv.mkDerivation rec {
     DiskArbitration
   ]);
 
+  passthru = {
+    propagateEnv = {
+      GST_PLUGIN_SYSTEM_PATH_1_0 = "@out@/lib/gstreamer-1.0";
+    };
+  };
+
   mesonFlags = [
     "-Dexamples=disabled" # requires many dependencies and probably not useful for our users
     "-Dsidplay=disabled" # sidplay / sidplay/player.h isn't packaged in nixpkgs as of writing
diff --git a/pkgs/development/libraries/gstreamer/vaapi/default.nix b/pkgs/development/libraries/gstreamer/vaapi/default.nix
index cac56f64cc91c..2095378654d8d 100644
--- a/pkgs/development/libraries/gstreamer/vaapi/default.nix
+++ b/pkgs/development/libraries/gstreamer/vaapi/default.nix
@@ -62,6 +62,12 @@ stdenv.mkDerivation rec {
     "-Dexamples=disabled" # requires many dependencies and probably not useful for our users
   ];
 
+  passthru = {
+    propagateEnv = {
+      GST_PLUGIN_SYSTEM_PATH_1_0 = "@out@/lib/gstreamer-1.0";
+    };
+  };
+
   meta = with stdenv.lib; {
     description = "Set of VAAPI GStreamer Plug-ins";
     homepage = "https://gstreamer.freedesktop.org";
diff --git a/pkgs/development/libraries/gtk/3.x.nix b/pkgs/development/libraries/gtk/3.x.nix
index fc3d79891e44c..0ca84923f5e1c 100644
--- a/pkgs/development/libraries/gtk/3.x.nix
+++ b/pkgs/development/libraries/gtk/3.x.nix
@@ -189,6 +189,10 @@ stdenv.mkDerivation rec {
       packageName = "gtk+";
       attrPath = "gtk3";
     };
+    propagateEnv = {
+      XDG_DATA_DIRS = "@out@/share/gsettings-schemas/${pname}-${version}";
+      GI_TYPELIB_PATH = "@out@/lib/girepository-1.0";
+    };
   };
 
   meta = {
diff --git a/pkgs/development/libraries/gvfs/default.nix b/pkgs/development/libraries/gvfs/default.nix
index 1caed4cacf7aa..9904e40550ab7 100644
--- a/pkgs/development/libraries/gvfs/default.nix
+++ b/pkgs/development/libraries/gvfs/default.nix
@@ -120,6 +120,9 @@ stdenv.mkDerivation rec {
     updateScript = gnome3.updateScript {
       packageName = pname;
     };
+    propagateEnv = {
+      GIO_EXTRA_MODULES = "@out@/lib/gio/modules";
+    };
   };
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/libraries/librsvg/default.nix b/pkgs/development/libraries/librsvg/default.nix
index 911286efb7fc5..1f45849e04611 100644
--- a/pkgs/development/libraries/librsvg/default.nix
+++ b/pkgs/development/libraries/librsvg/default.nix
@@ -76,6 +76,10 @@ stdenv.mkDerivation rec {
     updateScript = gnome3.updateScript {
       packageName = pname;
     };
+    propagateEnv = {
+      GDK_PIXBUF_MODULE_FILE = "@out@/${gdk-pixbuf.cacheFile}";
+      GI_TYPELIB_PATH = "@out@/lib/girepository-1.0";
+    };
   };
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/libraries/pango/default.nix b/pkgs/development/libraries/pango/default.nix
index 358ae3df99112..0e142cf1023b6 100644
--- a/pkgs/development/libraries/pango/default.nix
+++ b/pkgs/development/libraries/pango/default.nix
@@ -54,6 +54,9 @@ in stdenv.mkDerivation rec {
     updateScript = gnome3.updateScript {
       packageName = pname;
     };
+    propagateEnv = {
+      GI_TYPELIB_PATH = "@out@/lib/girepository-1.0";
+    };
   };
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/libraries/qt-5/modules/qtbase.nix b/pkgs/development/libraries/qt-5/modules/qtbase.nix
index a4c12793abb3b..77eab41278efd 100644
--- a/pkgs/development/libraries/qt-5/modules/qtbase.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtbase.nix
@@ -35,7 +35,7 @@ let
     if compareVersion "5.12.4" < 0 then ".qmake.cache" else ".qmake.stash";
 in
 
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
 
   name = "qtbase-${version}";
   inherit qtCompatVersion src version;
@@ -161,6 +161,12 @@ stdenv.mkDerivation {
   qtPluginPrefix = "lib/qt-${qtCompatVersion}/plugins";
   qtQmlPrefix = "lib/qt-${qtCompatVersion}/qml";
   qtDocPrefix = "share/doc/qt-${qtCompatVersion}";
+  passthru = {
+    propagateEnv = {
+      QT_PLUGIN_PATH = "@bin@/${qtPluginPrefix}";
+      # QML2_IMPORT_PATH = "@bin@/${qtQmlPrefix}";
+    };
+  };
 
   setOutputFlags = false;
   preConfigure = ''
diff --git a/pkgs/development/libraries/qt-5/modules/qtcharts.nix b/pkgs/development/libraries/qt-5/modules/qtcharts.nix
index 84d3a17ea8cef..14ebe8d69948a 100644
--- a/pkgs/development/libraries/qt-5/modules/qtcharts.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtcharts.nix
@@ -4,4 +4,10 @@ qtModule {
   name = "qtcharts";
   qtInputs = [ qtbase qtdeclarative ];
   outputs = [ "out" "dev" "bin" ];
+  passthru = {
+    propagateEnv = {
+      QT_PLUGIN_PATH = "@bin@/${qtbase.qtPluginPrefix}";
+      QML2_IMPORT_PATH = "@bin@/${qtbase.qtQmlPrefix}";
+    };
+  };
 }
diff --git a/pkgs/development/libraries/qt-5/modules/qtdeclarative.nix b/pkgs/development/libraries/qt-5/modules/qtdeclarative.nix
index b611282294c65..889b56f268f45 100644
--- a/pkgs/development/libraries/qt-5/modules/qtdeclarative.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtdeclarative.nix
@@ -23,4 +23,10 @@ qtModule {
     "bin/qmlscene"
     "bin/qmltestrunner"
   ];
+  passthru = {
+    propagateEnv = {
+      QT_PLUGIN_PATH = "@bin@/${qtbase.qtPluginPrefix}";
+      QML2_IMPORT_PATH = "@bin@/${qtbase.qtQmlPrefix}";
+    };
+  };
 }
diff --git a/pkgs/development/libraries/qt-5/modules/qtmultimedia.nix b/pkgs/development/libraries/qt-5/modules/qtmultimedia.nix
index d0bab88b2f214..6919ed9328f53 100644
--- a/pkgs/development/libraries/qt-5/modules/qtmultimedia.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtmultimedia.nix
@@ -13,4 +13,10 @@ qtModule {
   outputs = [ "bin" "dev" "out" ];
   qmakeFlags = [ "GST_VERSION=1.0" ];
   NIX_LDFLAGS = optionalString (stdenv.isDarwin) "-lobjc";
+  passthru = {
+    propagateEnv = {
+      QT_PLUGIN_PATH = "@bin@/${qtbase.qtPluginPrefix}";
+      QML2_IMPORT_PATH = "@bin@/${qtbase.qtQmlPrefix}";
+    };
+  };
 }
diff --git a/pkgs/development/libraries/qt-5/modules/qtquickcontrols2.nix b/pkgs/development/libraries/qt-5/modules/qtquickcontrols2.nix
index a9522f4b1f0cd..e2794c6ccb7e1 100644
--- a/pkgs/development/libraries/qt-5/modules/qtquickcontrols2.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtquickcontrols2.nix
@@ -1,7 +1,13 @@
-{ qtModule, qtdeclarative }:
+{ qtModule, qtdeclarative, qtbase }:
 
 qtModule {
   name = "qtquickcontrols2";
   qtInputs = [ qtdeclarative ];
   outputs = [ "out" "dev" "bin" ];
+  passthru = {
+    propagateEnv = {
+      # QT_PLUGIN_PATH = "@bin@/${qtbase.qtPluginPrefix}";
+      QML2_IMPORT_PATH = "@bin@/${qtbase.qtQmlPrefix}";
+    };
+  };
 }
diff --git a/pkgs/development/libraries/qt-5/modules/qtsvg.nix b/pkgs/development/libraries/qt-5/modules/qtsvg.nix
index 3ce68e56e4126..827d0f4c1ec9f 100644
--- a/pkgs/development/libraries/qt-5/modules/qtsvg.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtsvg.nix
@@ -4,4 +4,10 @@ qtModule {
   name = "qtsvg";
   qtInputs = [ qtbase ];
   outputs = [ "out" "dev" "bin" ];
+  passthru = {
+    propagateEnv = {
+      QT_PLUGIN_PATH = "@bin@/${qtbase.qtPluginPrefix}";
+      # QML2_IMPORT_PATH = "@bin@/${qtbase.qtQmlPrefix}";
+    };
+  };
 }
diff --git a/pkgs/development/libraries/qt-5/modules/qtwayland.nix b/pkgs/development/libraries/qt-5/modules/qtwayland.nix
index c7a7704f28372..0a848b2b11b87 100644
--- a/pkgs/development/libraries/qt-5/modules/qtwayland.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtwayland.nix
@@ -6,4 +6,10 @@ qtModule {
   buildInputs = [ wayland ];
   nativeBuildInputs = [ pkgconfig ];
   outputs = [ "out" "dev" "bin" ];
+  passthru = {
+    propagateEnv = {
+      QT_PLUGIN_PATH = "@bin@/${qtbase.qtPluginPrefix}";
+      QML2_IMPORT_PATH = "@bin@/${qtbase.qtQmlPrefix}";
+    };
+  };
 }
diff --git a/pkgs/development/python-modules/Babel/default.nix b/pkgs/development/python-modules/Babel/default.nix
index 1074d2eef48c8..d25ad2a4ba71a 100644
--- a/pkgs/development/python-modules/Babel/default.nix
+++ b/pkgs/development/python-modules/Babel/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, lib, buildPythonPackage, fetchPypi, fetchpatch, pytz, pytest, freezegun, glibcLocales }:
+{ stdenv, python, lib, buildPythonPackage, fetchPypi, fetchpatch, pytz, pytest, freezegun, glibcLocales }:
 
 buildPythonPackage rec {
   pname = "Babel";
@@ -29,6 +29,11 @@ buildPythonPackage rec {
       sha256 = "09yny8614knr8ngrrddmqzkxk70am135rccv2ncc6dji4xbqbfln";
     })
   ];
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   propagatedBuildInputs = [ pytz ];
 
diff --git a/pkgs/development/python-modules/alabaster/default.nix b/pkgs/development/python-modules/alabaster/default.nix
index d54741b63ea2c..1c4be72668d87 100644
--- a/pkgs/development/python-modules/alabaster/default.nix
+++ b/pkgs/development/python-modules/alabaster/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, fetchPypi
+{ stdenv, buildPythonPackage, fetchPypi, python
 , pygments }:
 
 buildPythonPackage rec {
@@ -14,6 +14,11 @@ buildPythonPackage rec {
 
   # No tests included
   doCheck = false;
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = with stdenv.lib; {
     homepage = "https://github.com/bitprophet/alabaster";
diff --git a/pkgs/development/python-modules/certifi/default.nix b/pkgs/development/python-modules/certifi/default.nix
index 35df76e68cdbe..fc85208742044 100644
--- a/pkgs/development/python-modules/certifi/default.nix
+++ b/pkgs/development/python-modules/certifi/default.nix
@@ -1,6 +1,7 @@
 { lib
 , fetchPypi
 , buildPythonPackage
+, python
 }:
 
 buildPythonPackage rec {
@@ -11,6 +12,11 @@ buildPythonPackage rec {
     inherit pname version;
     sha256 = "25b64c7da4cd7479594d035c08c2d809eb4aab3a26e5a990ea98cc450c320f1f";
   };
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = {
     homepage = "http://certifi.io/";
diff --git a/pkgs/development/python-modules/chardet/default.nix b/pkgs/development/python-modules/chardet/default.nix
index 1a8b1f36e998c..7794df8e2d76b 100644
--- a/pkgs/development/python-modules/chardet/default.nix
+++ b/pkgs/development/python-modules/chardet/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, fetchPypi, fetchpatch
+{ stdenv, buildPythonPackage, fetchPypi, fetchpatch, python
 , pytest, pytestrunner, hypothesis }:
 
 buildPythonPackage rec {
@@ -9,6 +9,11 @@ buildPythonPackage rec {
     inherit pname version;
     sha256 = "1bpalpia6r5x1kknbk11p1fzph56fmmnp405ds8icksd3knr5aw4";
   };
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   patches = [
     # Add pytest 4 support. See: https://github.com/chardet/chardet/pull/174
diff --git a/pkgs/development/python-modules/cycler/default.nix b/pkgs/development/python-modules/cycler/default.nix
index 643a57e259ff5..ea267d1d37736 100644
--- a/pkgs/development/python-modules/cycler/default.nix
+++ b/pkgs/development/python-modules/cycler/default.nix
@@ -27,6 +27,12 @@ buildPythonPackage rec {
   # https://github.com/matplotlib/cycler/issues/31
   doCheck = false;
 
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
+
   meta = {
     description = "Composable style cycles";
     homepage = "https://github.com/matplotlib/cycler";
diff --git a/pkgs/development/python-modules/dateutil/default.nix b/pkgs/development/python-modules/dateutil/default.nix
index 88024265d9482..93062a57fa071 100644
--- a/pkgs/development/python-modules/dateutil/default.nix
+++ b/pkgs/development/python-modules/dateutil/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, fetchPypi, six, setuptools_scm, pytest }:
+{ stdenv, buildPythonPackage, fetchPypi, six, setuptools_scm, pytest, python }:
 buildPythonPackage rec {
   pname = "python-dateutil";
   version = "2.8.1";
@@ -17,6 +17,11 @@ buildPythonPackage rec {
 
   # Requires fixing
   doCheck = false;
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = with stdenv.lib; {
     description = "Powerful extensions to the standard datetime module";
diff --git a/pkgs/development/python-modules/dbus/default.nix b/pkgs/development/python-modules/dbus/default.nix
index 855ee930b7725..23a4e1c3421e3 100644
--- a/pkgs/development/python-modules/dbus/default.nix
+++ b/pkgs/development/python-modules/dbus/default.nix
@@ -19,6 +19,12 @@ buildPythonPackage rec {
 
   disabled = isPyPy;
 
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
+
   nativeBuildInputs = [ pkgconfig ];
   buildInputs = [ dbus dbus-glib ]
     # My guess why it's sometimes trying to -lncurses.
diff --git a/pkgs/development/python-modules/discid/default.nix b/pkgs/development/python-modules/discid/default.nix
index 2684d4a06a911..d37c0ebea5f20 100644
--- a/pkgs/development/python-modules/discid/default.nix
+++ b/pkgs/development/python-modules/discid/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, libdiscid, buildPythonPackage, fetchPypi }:
+{ stdenv, libdiscid, buildPythonPackage, fetchPypi, python }:
 
 buildPythonPackage rec {
   pname = "discid";
@@ -8,6 +8,11 @@ buildPythonPackage rec {
     inherit pname version;
     sha256 = "1fc6kvnqwaz9lrs2qgsp8wh0nabf49010r0r53wnsmpmafy315nd";
   };
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   patchPhase =
     let extension = stdenv.hostPlatform.extensions.sharedLibrary; in
diff --git a/pkgs/development/python-modules/docutils/default.nix b/pkgs/development/python-modules/docutils/default.nix
index 8c1fb3720ca12..54db9e15cd893 100644
--- a/pkgs/development/python-modules/docutils/default.nix
+++ b/pkgs/development/python-modules/docutils/default.nix
@@ -21,6 +21,11 @@ buildPythonPackage rec {
   checkPhase = lib.optionalString (isPy3k && stdenv.isDarwin) ''LANG="en_US.UTF-8" LC_ALL="en_US.UTF-8" '' + ''
     ${python.interpreter} test/alltests.py
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   # Create symlinks lacking a ".py" suffix, many programs depend on these names
   postFixup = ''
diff --git a/pkgs/development/python-modules/html5lib/default.nix b/pkgs/development/python-modules/html5lib/default.nix
index 81042ac340983..6ebf1b77c8882 100644
--- a/pkgs/development/python-modules/html5lib/default.nix
+++ b/pkgs/development/python-modules/html5lib/default.nix
@@ -7,6 +7,7 @@
 , mock
 , six
 , webencodings
+, python
 }:
 
 buildPythonPackage rec {
@@ -29,6 +30,11 @@ buildPythonPackage rec {
     rm html5lib/tests/test_stream.py
     py.test
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = {
     homepage = "https://github.com/html5lib/html5lib-python";
diff --git a/pkgs/development/python-modules/idna/default.nix b/pkgs/development/python-modules/idna/default.nix
index 5e5d623ff10e8..54d357750d5d8 100644
--- a/pkgs/development/python-modules/idna/default.nix
+++ b/pkgs/development/python-modules/idna/default.nix
@@ -1,6 +1,7 @@
 { lib
 , buildPythonPackage
 , fetchPypi
+, python
 }:
 
 buildPythonPackage rec {
@@ -11,10 +12,15 @@ buildPythonPackage rec {
     inherit pname version;
     sha256 = "c357b3f628cf53ae2c4c05627ecc484553142ca23264e593d327bcde5e9c3407";
   };
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = {
     homepage = "https://github.com/kjd/idna/";
     description = "Internationalized Domain Names in Applications (IDNA)";
     license = lib.licenses.bsd3;
   };
-}
\ No newline at end of file
+}
diff --git a/pkgs/development/python-modules/imagesize/default.nix b/pkgs/development/python-modules/imagesize/default.nix
index aa7f1ea472491..a711eff68f981 100644
--- a/pkgs/development/python-modules/imagesize/default.nix
+++ b/pkgs/development/python-modules/imagesize/default.nix
@@ -1,6 +1,7 @@
 { stdenv
 , buildPythonPackage
 , fetchPypi
+, python
 }:
 
 buildPythonPackage rec {
@@ -11,6 +12,11 @@ buildPythonPackage rec {
     inherit pname version;
     sha256 = "f3832918bc3c66617f92e35f5d70729187676313caa60c187eb0f28b8fe5e3b5";
   };
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = with stdenv.lib; {
     description = "Getting image size from png/jpeg/jpeg2000/gif file";
diff --git a/pkgs/development/python-modules/jinja2/default.nix b/pkgs/development/python-modules/jinja2/default.nix
index 87c44d11a8c8d..28d77b90ff6d4 100644
--- a/pkgs/development/python-modules/jinja2/default.nix
+++ b/pkgs/development/python-modules/jinja2/default.nix
@@ -3,6 +3,7 @@
 , isPy3k
 , fetchPypi
 , pytest
+, python
 , markupsafe }:
 
 buildPythonPackage rec {
@@ -24,6 +25,11 @@ buildPythonPackage rec {
   checkPhase = ''
     pytest -v tests
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = with stdenv.lib; {
     homepage = "http://jinja.pocoo.org/";
diff --git a/pkgs/development/python-modules/kiwisolver/default.nix b/pkgs/development/python-modules/kiwisolver/default.nix
index c54cad1987aa8..1a1d341fe586f 100644
--- a/pkgs/development/python-modules/kiwisolver/default.nix
+++ b/pkgs/development/python-modules/kiwisolver/default.nix
@@ -3,6 +3,7 @@
 , fetchPypi
 , stdenv
 , libcxx
+, python
 }:
 
 buildPythonPackage rec {
@@ -18,6 +19,11 @@ buildPythonPackage rec {
   
   # Does not include tests
   doCheck = false;
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = {
     description = "A fast implementation of the Cassowary constraint solver";
diff --git a/pkgs/development/python-modules/matplotlib/default.nix b/pkgs/development/python-modules/matplotlib/default.nix
index 658388eabae4a..822283ee91b18 100644
--- a/pkgs/development/python-modules/matplotlib/default.nix
+++ b/pkgs/development/python-modules/matplotlib/default.nix
@@ -34,9 +34,7 @@ buildPythonPackage rec {
 
   XDG_RUNTIME_DIR = "/tmp";
 
-  nativeBuildInputs = [ pkgconfig ];
-
-  buildInputs = [ python which sphinx stdenv ]
+  nativeBuildInputs = [ pkgconfig python which sphinx stdenv ]
     ++ stdenv.lib.optional enableGhostscript ghostscript
     ++ stdenv.lib.optional stdenv.isDarwin [ Cocoa ];
 
@@ -48,6 +46,12 @@ buildPythonPackage rec {
     ++ stdenv.lib.optionals enableTk [ tcl tk tkinter libX11 ]
     ++ stdenv.lib.optionals enableQt [ pyqt5 ];
 
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
+
   patches =
     [ ./basedirlist.patch ];
 
diff --git a/pkgs/development/python-modules/mock/default.nix b/pkgs/development/python-modules/mock/default.nix
index de1ff58243e67..b07843c684e1a 100644
--- a/pkgs/development/python-modules/mock/default.nix
+++ b/pkgs/development/python-modules/mock/default.nix
@@ -28,6 +28,11 @@ buildPythonPackage rec {
   checkPhase = ''
     ${python.interpreter} -m unittest discover
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = with lib; {
     description = "Mock objects for Python";
diff --git a/pkgs/development/python-modules/mutagen/default.nix b/pkgs/development/python-modules/mutagen/default.nix
index 304aeead76ff0..dacc2f5fd3a0b 100644
--- a/pkgs/development/python-modules/mutagen/default.nix
+++ b/pkgs/development/python-modules/mutagen/default.nix
@@ -8,6 +8,7 @@
 , pytest
 , setuptools
 , pkgs
+, python
 }:
 
 buildPythonPackage rec {
@@ -25,6 +26,12 @@ buildPythonPackage rec {
     pkgs.glibcLocales pycodestyle pyflakes pytest hypothesis
   ];
   LC_ALL = "en_US.UTF-8";
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
+
 
   meta = with lib; {
     description = "Python multimedia tagging library";
diff --git a/pkgs/development/python-modules/numpy/default.nix b/pkgs/development/python-modules/numpy/default.nix
index a863ef60d4aa7..9986b081a9147 100644
--- a/pkgs/development/python-modules/numpy/default.nix
+++ b/pkgs/development/python-modules/numpy/default.nix
@@ -70,6 +70,9 @@ in buildPythonPackage rec {
   passthru = {
     blas = blas;
     inherit blasImplementation cfg;
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
   };
 
   # Disable test
diff --git a/pkgs/development/python-modules/pycairo/default.nix b/pkgs/development/python-modules/pycairo/default.nix
index fbefd7efefa66..03a3aaf60e2c7 100644
--- a/pkgs/development/python-modules/pycairo/default.nix
+++ b/pkgs/development/python-modules/pycairo/default.nix
@@ -1,4 +1,4 @@
-{ lib, fetchFromGitHub, meson, ninja, buildPythonPackage, pytest, pkgconfig, cairo, xlibsWrapper, isPy33, isPy3k }:
+{ lib, fetchFromGitHub, meson, ninja, buildPythonPackage, pytest, python, pkgconfig, cairo, xlibsWrapper, isPy33, isPy3k }:
 
 buildPythonPackage rec {
   pname = "pycairo";
@@ -26,6 +26,12 @@ buildPythonPackage rec {
     xlibsWrapper
   ];
 
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
+
   checkInputs = [ pytest ];
 
   mesonFlags = [ "-Dpython=${if isPy3k then "python3" else "python"}" ];
diff --git a/pkgs/development/python-modules/pygobject/3.nix b/pkgs/development/python-modules/pygobject/3.nix
index 2a1b8bcb4105f..a0916d6444833 100644
--- a/pkgs/development/python-modules/pygobject/3.nix
+++ b/pkgs/development/python-modules/pygobject/3.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, buildPythonPackage, pkgconfig, glib, gobject-introspection,
+{ stdenv, fetchurl, buildPythonPackage, pkgconfig, glib, gobject-introspection, python,
 pycairo, cairo, which, ncurses, meson, ninja, isPy3k, gnome3 }:
 
 buildPythonPackage rec {
@@ -28,6 +28,9 @@ buildPythonPackage rec {
       packageName = pname;
       attrPath = "python3.pkgs.${pname}3";
     };
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
   };
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/python-modules/pyparsing/default.nix b/pkgs/development/python-modules/pyparsing/default.nix
index 4acc4fa804b36..5dae0cc9e3a58 100644
--- a/pkgs/development/python-modules/pyparsing/default.nix
+++ b/pkgs/development/python-modules/pyparsing/default.nix
@@ -1,7 +1,7 @@
 { buildPythonPackage
 , fetchFromGitHub
 , lib
-
+, python
 # pythonPackages
 , coverage
 }:
@@ -23,6 +23,11 @@ buildPythonPackage rec {
     coverage run --branch simple_unit_tests.py
     coverage run --branch unitTests.py
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = with lib; {
     homepage = "https://github.com/pyparsing/pyparsing";
diff --git a/pkgs/development/python-modules/pyqt/5.x.nix b/pkgs/development/python-modules/pyqt/5.x.nix
index 52b27638ac72e..94573672a62dc 100644
--- a/pkgs/development/python-modules/pyqt/5.x.nix
+++ b/pkgs/development/python-modules/pyqt/5.x.nix
@@ -88,7 +88,7 @@ in buildPythonPackage rec {
   configurePhase = ''
     runHook preConfigure
 
-    export PYTHONPATH=$PYTHONPATH:$out/${python.sitePackages}
+    export NIX_PYTHONPATH=$NIX_PYTHONPATH:$out/${python.sitePackages}
 
     ${python.executable} configure.py  -w \
       --confirm-license \
@@ -106,7 +106,7 @@ in buildPythonPackage rec {
   postInstall = ''
     ln -s ${sip}/${python.sitePackages}/PyQt5/sip.* $out/${python.sitePackages}/PyQt5/
     for i in $out/bin/*; do
-      wrapProgram $i --prefix PYTHONPATH : "$PYTHONPATH"
+      wrapProgram $i --prefix NIX_PYTHONPATH : "$NIX_PYTHONPATH"
     done
 
     # Let's make it a namespace package
@@ -135,6 +135,12 @@ in buildPythonPackage rec {
     ${python.interpreter} -c "${imports}"
   '';
 
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
+
   doCheck = true;
 
   enableParallelBuilding = true;
diff --git a/pkgs/development/python-modules/pytz/default.nix b/pkgs/development/python-modules/pytz/default.nix
index e7ce3b62b5b8d..dd46a80162901 100644
--- a/pkgs/development/python-modules/pytz/default.nix
+++ b/pkgs/development/python-modules/pytz/default.nix
@@ -12,6 +12,11 @@ buildPythonPackage rec {
   checkPhase = ''
     ${python.interpreter} -m unittest discover -s pytz/tests
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = with lib; {
     description = "World timezone definitions, modern and historical";
diff --git a/pkgs/development/python-modules/requests/default.nix b/pkgs/development/python-modules/requests/default.nix
index 3d216e4bc44f8..064c5c4446052 100644
--- a/pkgs/development/python-modules/requests/default.nix
+++ b/pkgs/development/python-modules/requests/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchPypi, buildPythonPackage
+{ stdenv, fetchPypi, buildPythonPackage, python
 , urllib3, idna, chardet, certifi
 , pytest }:
 
@@ -10,6 +10,11 @@ buildPythonPackage rec {
     inherit pname version;
     sha256 = "11e007a8a2aa0323f5a921e9e6a2d7e4e67d9877e85773fba9ba6419025cbeb4";
   };
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   nativeBuildInputs = [ pytest ];
   propagatedBuildInputs = [ urllib3 idna chardet certifi ];
diff --git a/pkgs/development/python-modules/setuptools/default.nix b/pkgs/development/python-modules/setuptools/default.nix
index c4ff18697e564..c35f819bab44d 100644
--- a/pkgs/development/python-modules/setuptools/default.nix
+++ b/pkgs/development/python-modules/setuptools/default.nix
@@ -55,6 +55,11 @@ in buildPythonPackage rec {
   preBuild = lib.strings.optionalString (!stdenv.hostPlatform.isWindows) ''
     export SETUPTOOLS_INSTALL_WINDOWS_SPECIFIC_FILES=0
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   pipInstallFlags = [ "--ignore-installed" ];
 
diff --git a/pkgs/development/python-modules/simplejson/default.nix b/pkgs/development/python-modules/simplejson/default.nix
index fe08f5bbe2e53..6de9b8ace649b 100644
--- a/pkgs/development/python-modules/simplejson/default.nix
+++ b/pkgs/development/python-modules/simplejson/default.nix
@@ -3,6 +3,7 @@
 , fetchFromGitHub
 , stdenv
 , pytest
+, python
 }:
 
 buildPythonPackage rec {
@@ -24,6 +25,11 @@ buildPythonPackage rec {
   checkPhase = ''
     PYTHONWARNINGS="ignore" pytest simplejson/tests
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = {
     description = "A simple, fast, extensible JSON encoder/decoder for Python";
diff --git a/pkgs/development/python-modules/six/default.nix b/pkgs/development/python-modules/six/default.nix
index 46f7f6d38b6bb..29b700d900fb1 100644
--- a/pkgs/development/python-modules/six/default.nix
+++ b/pkgs/development/python-modules/six/default.nix
@@ -1,6 +1,7 @@
 { lib
 , buildPythonPackage
 , fetchPypi
+, python
 , pytest
 }:
 
@@ -18,6 +19,11 @@ buildPythonPackage rec {
   checkPhase = ''
     py.test test_six.py
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   # To prevent infinite recursion with pytest
   doCheck = false;
diff --git a/pkgs/development/python-modules/snowballstemmer/default.nix b/pkgs/development/python-modules/snowballstemmer/default.nix
index c546fefcf5034..499b8b77b05a8 100644
--- a/pkgs/development/python-modules/snowballstemmer/default.nix
+++ b/pkgs/development/python-modules/snowballstemmer/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, PyStemmer, fetchPypi }:
+{ stdenv, python, buildPythonPackage, PyStemmer, fetchPypi }:
 
 buildPythonPackage rec {
   pname = "snowballstemmer";
@@ -12,6 +12,12 @@ buildPythonPackage rec {
   # No tests included
   doCheck = false;
 
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
+
   propagatedBuildInputs = [ PyStemmer ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/python-modules/sphinx/default.nix b/pkgs/development/python-modules/sphinx/default.nix
index 9c7d699d20f03..b3d0821583409 100644
--- a/pkgs/development/python-modules/sphinx/default.nix
+++ b/pkgs/development/python-modules/sphinx/default.nix
@@ -39,6 +39,11 @@ buildPythonPackage rec {
     sha256 = "19a28nsb0w4bs6k8rdfyk6vzrcwdpvhs2wq77rgpmww59yvndrz6";
   };
   LC_ALL = "en_US.UTF-8";
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   checkInputs = [ pytest ];
   buildInputs = [ simplejson mock glibcLocales html5lib ] ++ lib.optional (pythonOlder "3.4") enum34;
diff --git a/pkgs/development/python-modules/tkinter/default.nix b/pkgs/development/python-modules/tkinter/default.nix
index 1efebed987218..3d24d4060a674 100644
--- a/pkgs/development/python-modules/tkinter/default.nix
+++ b/pkgs/development/python-modules/tkinter/default.nix
@@ -23,6 +23,11 @@ buildPythonPackage {
     new_rpath=$(sed "s#${py}#${python}#g" <<< "$old_rpath" )
     patchelf --set-rpath $new_rpath $out/${py.sitePackages}/_tkinter*
   '';
+  passthru = {
+    propagateEnv = {
+      PYTHONPATH = "@out@/${py.sitePackages}";
+    };
+  };
 
   meta = py.meta;
 
diff --git a/pkgs/development/python-modules/tornado/default.nix b/pkgs/development/python-modules/tornado/default.nix
index 102cf0fed5740..44aea604aa440 100644
--- a/pkgs/development/python-modules/tornado/default.nix
+++ b/pkgs/development/python-modules/tornado/default.nix
@@ -37,6 +37,11 @@ buildPythonPackage rec {
   checkPhase = ''
     ${python.interpreter} -m unittest discover *_test.py
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   src = fetchPypi {
     inherit pname sha256 version;
diff --git a/pkgs/development/python-modules/urllib3/default.nix b/pkgs/development/python-modules/urllib3/default.nix
index 5abf99670c19b..04659a7942612 100644
--- a/pkgs/development/python-modules/urllib3/default.nix
+++ b/pkgs/development/python-modules/urllib3/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, fetchPypi
+{ stdenv, buildPythonPackage, fetchPypi, python
 , pytest, mock, tornado, pyopenssl, cryptography
 , idna, certifi, ipaddress, pysocks }:
 
@@ -10,6 +10,11 @@ buildPythonPackage rec {
     inherit pname version;
     sha256 = "87716c2d2a7121198ebcb7ce7cccf6ce5e9ba539041cfbaeecfb641dc0bf6acc";
   };
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   NOSE_EXCLUDE = stdenv.lib.concatStringsSep "," [
     "test_headers" "test_headerdict" "test_can_validate_ip_san" "test_delayed_body_read_timeout"
diff --git a/pkgs/development/python-modules/whoosh/default.nix b/pkgs/development/python-modules/whoosh/default.nix
index e203cdb293441..96de28ac55e64 100644
--- a/pkgs/development/python-modules/whoosh/default.nix
+++ b/pkgs/development/python-modules/whoosh/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, fetchPypi, pytest }:
+{ stdenv, buildPythonPackage, fetchPypi, pytest, python }:
 
 buildPythonPackage rec {
   pname = "Whoosh";
@@ -19,6 +19,11 @@ buildPythonPackage rec {
     # FIXME: test_minimize_dfa fails on python 3.6
     py.test -k "not test_timelimit and not test_minimize_dfa"
   '';
+  passthru = {
+    propagateEnv = {
+      NIX_PYTHONPATH = "@out@/${python.sitePackages}";
+    };
+  };
 
   meta = with stdenv.lib; {
     description = "Fast, pure-Python full text indexing, search, and spell
diff --git a/pkgs/tools/X11/arandr/default.nix b/pkgs/tools/X11/arandr/default.nix
index 94e3ac36d078b..853d18e09bec3 100644
--- a/pkgs/tools/X11/arandr/default.nix
+++ b/pkgs/tools/X11/arandr/default.nix
@@ -23,6 +23,8 @@ in buildPythonApplication rec {
   # no tests
   doCheck = false;
 
+  dontWrapPythonPrograms = (wrapGAppsHook == null);
+
   # hook for gobject-introspection doesn't like strictDeps
   # https://github.com/NixOS/nixpkgs/issues/56943
   strictDeps = false;
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index b22a35f4f5e4a..c2d31cc6e340a 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -659,7 +659,18 @@ in
 
   archivemount = callPackage ../tools/filesystems/archivemount { };
 
-  arandr = callPackage ../tools/X11/arandr { };
+  arandr-oldy-wrapped = callPackage ../tools/X11/arandr { };
+
+  arandr-newly-wrapped = wrapGApps (
+    arandr-oldy-wrapped.override {
+      wrapGAppsHook = null;
+    }) {
+      wrapOut = {
+        XDG_DATA_DIRS = "$out/share";
+        NIX_PYTHONPATH = "$out/${python3.sitePackages}";
+      };
+    }
+  ;
 
   inherit (callPackages ../servers/nosql/arangodb {
     stdenv = gcc8Stdenv;
@@ -19748,7 +19759,7 @@ in
 
   gvisor-containerd-shim = callPackage ../applications/virtualization/gvisor/containerd-shim.nix { };
 
-  guvcview = callPackage ../os-specific/linux/guvcview { };
+  guvcview = wrapGApps (callPackage ../os-specific/linux/guvcview { }) {  };
 
   gxmessage = callPackage ../applications/misc/gxmessage { };
 
@@ -21191,7 +21202,44 @@ in
 
   pianobooster = qt5.callPackage ../applications/audio/pianobooster { };
 
-  picard = callPackage ../applications/audio/picard { };
+  test-new-py-env = wrapGeneric python3 {
+    linkByEnv = {
+      PYTHONPATH = "linkPkg";
+    };
+    extraPkgs = with python3.pkgs; [
+      # Note how when you use matplot with and without qt, the environment
+      # calculated in `result/bin/python` has QT_PLUGIN_PATH and other env
+      # vars.
+
+      # matplotlib
+      (matplotlib.override {
+        enableQt = true;
+      })
+    ];
+  };
+  test-old-py-env = python3.withPackages(ps: with ps; [
+    (matplotlib.override {
+      enableQt = true;
+    })
+  ]);
+
+  picard-oldy-wrapped = callPackage ../applications/audio/picard { };
+
+  picard-newly-wrapped = wrapGeneric (
+    picard-oldy-wrapped.override {
+      qt5 = qt5 // {
+        wrapQtAppsHook = null;
+      };
+    }) {
+      wrapOut = {
+        XDG_DATA_DIRS = "$out/share";
+        NIX_PYTHONPATH = "$out/${python3.sitePackages}";
+      };
+      linkByEnv = {
+        NIX_PYTHONPATH = "linkPkg";
+      };
+    }
+  ;
 
   picocom = callPackage ../tools/misc/picocom {
     inherit (darwin.apple_sdk.frameworks) IOKit;
@@ -22274,6 +22322,16 @@ in
 
   wrapNeovim = callPackage ../applications/editors/neovim/wrapper.nix { };
 
+  wrapGeneric = callPackage ../build-support/neowrap.nix { lndir = xorg.lndir; };
+  wrapGApps = wrapGeneric.override {
+    extraPkgsByOverride = [
+      dconf
+      librsvg
+      gdk-pixbuf
+      atk
+    ];
+  };
+
   neovim-unwrapped = callPackage ../applications/editors/neovim {
     lua =
       # neovim doesn't work with luajit on aarch64: https://github.com/neovim/neovim/issues/7879