diff --git a/pkgs/applications/audio/flac/default.nix b/pkgs/applications/audio/flac/default.nix
index d4214729485..0383a1ce0ad 100644
--- a/pkgs/applications/audio/flac/default.nix
+++ b/pkgs/applications/audio/flac/default.nix
@@ -15,5 +15,6 @@ stdenv.mkDerivation rec {
   meta = {
     homepage = http://xiph.org/flac/;
     description = "Library and tools for encoding and decoding the FLAC lossless audio file format";
+    platforms = stdenv.lib.platforms.all;
   };
 }
diff --git a/pkgs/development/libraries/expat/default.nix b/pkgs/development/libraries/expat/default.nix
index 6b675230119..d7915a93962 100644
--- a/pkgs/development/libraries/expat/default.nix
+++ b/pkgs/development/libraries/expat/default.nix
@@ -11,5 +11,6 @@ stdenv.mkDerivation rec {
   meta = {
     homepage = http://www.libexpat.org/;
     description = "A stream-oriented XML parser library written in C";
+    platforms = stdenv.lib.platforms.all;
   };
 }
diff --git a/pkgs/development/libraries/fontconfig/default.nix b/pkgs/development/libraries/fontconfig/default.nix
index 2067f3457b6..e3b0a54ee82 100644
--- a/pkgs/development/libraries/fontconfig/default.nix
+++ b/pkgs/development/libraries/fontconfig/default.nix
@@ -18,8 +18,6 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ pkgconfig freetype expat ];
 
-  #propagatedBuildInputs = [ expat ]; # !!! shouldn't be necessary, but otherwise pango breaks
-
   configureFlags = "--sysconfdir=/etc --with-cache-dir=/var/cache/fontconfig --disable-docs --with-default-fonts=";
 
   # We should find a better way to access the arch reliably.
@@ -36,7 +34,7 @@ stdenv.mkDerivation rec {
   # Don't try to write to /etc/fonts or /var/cache/fontconfig at install time.
   installFlags = "sysconfdir=$(out)/etc RUN_FC_CACHE_TEST=false fc_cachedir=$(TMPDIR)/dummy";
 
-  postInstall = if !freetype.infinality.useInfinality then "" else ''
+  postInstall = stdenv.lib.optionalString freetype.infinality.useInfinality ''
     cd "$out/etc/fonts" && tar xvf ${infinality_patch}
   '';
 
@@ -44,5 +42,6 @@ stdenv.mkDerivation rec {
     description = "A library for font customization and configuration";
     homepage = http://fontconfig.org/;
     license = "bsd";
+    platforms = stdenv.lib.platforms.all;
   };
 }
diff --git a/pkgs/development/libraries/freetype/default.nix b/pkgs/development/libraries/freetype/default.nix
index cff22e9bc57..8fa75425544 100644
--- a/pkgs/development/libraries/freetype/default.nix
+++ b/pkgs/development/libraries/freetype/default.nix
@@ -75,5 +75,6 @@ stdenv.mkDerivation rec {
     homepage = http://www.freetype.org/;
     license = if useEncumberedCode then "unfree"
       else "GPLv2+"; # or the FreeType License (BSD + advertising clause)
+    platforms = stdenv.lib.platforms.all;
   };
 }
diff --git a/pkgs/development/libraries/gtk+/2.x.nix b/pkgs/development/libraries/gtk+/2.x.nix
index 055d93ef929..1cd85ae2aa5 100644
--- a/pkgs/development/libraries/gtk+/2.x.nix
+++ b/pkgs/development/libraries/gtk+/2.x.nix
@@ -52,6 +52,6 @@ stdenv.mkDerivation rec {
     license = "LGPLv2+";
 
     maintainers = [stdenv.lib.maintainers.raskin];
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.all;
   };
 }
diff --git a/pkgs/development/libraries/gtk+/3.x.nix b/pkgs/development/libraries/gtk+/3.x.nix
index a22e243411a..796b36f821c 100644
--- a/pkgs/development/libraries/gtk+/3.x.nix
+++ b/pkgs/development/libraries/gtk+/3.x.nix
@@ -45,6 +45,6 @@ stdenv.mkDerivation rec {
     license = "LGPLv2+";
 
     maintainers = with stdenv.lib.maintainers; [urkud raskin];
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.all;
   };
 }
diff --git a/pkgs/development/libraries/libpng/default.nix b/pkgs/development/libraries/libpng/default.nix
index 72821ef7028..0a150610781 100644
--- a/pkgs/development/libraries/libpng/default.nix
+++ b/pkgs/development/libraries/libpng/default.nix
@@ -20,5 +20,6 @@ stdenv.mkDerivation rec {
     description = "The official reference implementation for the PNG file format";
     homepage = http://www.libpng.org/pub/png/libpng.html;
     license = "free-non-copyleft"; # http://www.libpng.org/pub/png/src/libpng-LICENSE.txt
+    platforms = stdenv.lib.platforms.all;
   };
 }
diff --git a/pkgs/development/libraries/poppler/default.nix b/pkgs/development/libraries/poppler/default.nix
index 8e168c2f411..a871c0ab0d7 100644
--- a/pkgs/development/libraries/poppler/default.nix
+++ b/pkgs/development/libraries/poppler/default.nix
@@ -50,6 +50,7 @@ let
       '';
 
       license = "GPLv2";
+      platforms = stdenv.lib.platforms.all;
     };
   } merge ]); # poppler_drv
 
diff --git a/pkgs/tools/networking/curl/default.nix b/pkgs/tools/networking/curl/default.nix
index f9439f1b42a..73dcb44269c 100644
--- a/pkgs/tools/networking/curl/default.nix
+++ b/pkgs/tools/networking/curl/default.nix
@@ -66,5 +66,6 @@ stdenv.mkDerivation rec {
   meta = {
     homepage = "http://curl.haxx.se/";
     description = "A command line tool for transferring files with URL syntax";
+    platforms = stdenv.lib.platforms.all;
   };
 }