diff --git a/pkgs/development/libraries/glibc/default.nix b/pkgs/development/libraries/glibc/default.nix
index ea443ce9a24..c74c27598ee 100644
--- a/pkgs/development/libraries/glibc/default.nix
+++ b/pkgs/development/libraries/glibc/default.nix
@@ -5,8 +5,6 @@
 , withGd ? false
 }:
 
-assert stdenv.cc.isGNU;
-
 callPackage ./common.nix { inherit stdenv; } {
     name = "glibc" + stdenv.lib.optionalString withGd "-gd";
 
@@ -96,7 +94,8 @@ callPackage ./common.nix { inherit stdenv; } {
       mv $bin/bin/getconf_ $bin/bin/getconf
     '';
 
-    separateDebugInfo = true;
+    # Hack to get around eval issue.
+    separateDebugInfo = !stdenv.isDarwin;
 
     meta.description = "The GNU C Library";
   }
diff --git a/pkgs/os-specific/linux/kernel-headers/default.nix b/pkgs/os-specific/linux/kernel-headers/default.nix
index e82b785f624..09fa4fbfd3a 100644
--- a/pkgs/os-specific/linux/kernel-headers/default.nix
+++ b/pkgs/os-specific/linux/kernel-headers/default.nix
@@ -2,8 +2,6 @@
 , fetchurl, perl
 }:
 
-assert stdenvNoCC.hostPlatform.isLinux;
-
 let
   common = { version, sha256, patches ? null }: stdenvNoCC.mkDerivation {
     name = "linux-headers-${version}";
@@ -13,7 +11,7 @@ let
       inherit sha256;
     };
 
-    ARCH = stdenvNoCC.hostPlatform.platform.kernelArch;
+    ARCH = stdenvNoCC.hostPlatform.platform.kernelArch or (throw "missing kernelArch");
 
     # It may look odd that we use `stdenvNoCC`, and yet explicit depend on a cc.
     # We do this so we have a build->build, not build->host, C compiler.