diff --git a/pkgs/development/libraries/nss/default.nix b/pkgs/development/libraries/nss/default.nix
index 1bc934a6553..a504aae6a98 100644
--- a/pkgs/development/libraries/nss/default.nix
+++ b/pkgs/development/libraries/nss/default.nix
@@ -54,6 +54,11 @@ in stdenv.mkDerivation rec {
 
   patchFlags = [ "-p0" ];
 
+  postPatch = stdenv.lib.optionalString stdenv.hostPlatform.isDarwin ''
+     substituteInPlace nss/coreconf/Darwin.mk --replace '@executable_path/$(notdir $@)' "$out/lib/\$(notdir \$@)"
+     substituteInPlace nss/coreconf/config.gypi --replace "'DYLIB_INSTALL_NAME_BASE': '@executable_path'" "'DYLIB_INSTALL_NAME_BASE': '$out/lib'"
+   '';
+
   outputs = [ "out" "dev" "tools" ];
 
   preConfigure = "cd nss";
diff --git a/pkgs/development/python-modules/gyp/default.nix b/pkgs/development/python-modules/gyp/default.nix
index 8bb20fafe76..c951c97b20f 100644
--- a/pkgs/development/python-modules/gyp/default.nix
+++ b/pkgs/development/python-modules/gyp/default.nix
@@ -14,10 +14,6 @@ buildPythonPackage {
     sha256 = "0r9phq5yrmj968vdvy9vivli35wn1j9a6iwshp69wl7q4p0x8q2b";
   };
 
-  prePatch = stdenv.lib.optionals stdenv.isDarwin ''
-    sed -i 's/raise.*No Xcode or CLT version detected.*/version = "7.0.0"/' pylib/gyp/xcode_emulation.py
-  '';
-
   patches = stdenv.lib.optionals stdenv.isDarwin [
     ./no-darwin-cflags.patch
     ./no-xcode.patch
diff --git a/pkgs/development/python-modules/gyp/no-xcode.patch b/pkgs/development/python-modules/gyp/no-xcode.patch
index d202b722474..0e46865846a 100644
--- a/pkgs/development/python-modules/gyp/no-xcode.patch
+++ b/pkgs/development/python-modules/gyp/no-xcode.patch
@@ -1,12 +1,25 @@
---- a/pylib/gyp/xcode_emulation.py
-+++ b/pylib/gyp/xcode_emulation.py
-@@ -1470,7 +1470,8 @@
+--- gyp-old/pylib/gyp/xcode_emulation.py	1980-01-02 00:00:00.000000000 -0600
++++ gyp/pylib/gyp/xcode_emulation.py	2020-08-02 20:24:24.871322520 -0500
+@@ -1407,10 +1407,10 @@
+       raise GypError("xcodebuild returned unexpected results")
+   except:
+     version = CLTVersion()
+-    if version:
++    if version and re.match(r'(\d\.\d\.?\d*)', version):
+       version = re.match(r'(\d\.\d\.?\d*)', version).groups()[0]
+     else:
+-      raise GypError("No Xcode or CLT version detected!")
++      version = '7.0.0'
+     # The CLT has no build information, so we return an empty string.
+     version_list = [version, '']
+   version = version_list[0]
+@@ -1667,7 +1667,8 @@
      sdk_root = xcode_settings._SdkRoot(configuration)
      if not sdk_root:
        sdk_root = xcode_settings._XcodeSdkPath('')
 -    env['SDKROOT'] = sdk_root
-+    if sdk_root:
-+      env['SDKROOT'] = sdk_root
++    if not sdk_root:
++      env['SDKROOT'] = ''
  
    if not additional_settings:
      additional_settings = {}