diff --git a/pkgs/desktops/gnome-3/3.22/core/caribou/default.nix b/pkgs/desktops/gnome-3/3.22/core/caribou/default.nix
index 3f2831a6985..2d71f1da592 100644
--- a/pkgs/desktops/gnome-3/3.22/core/caribou/default.nix
+++ b/pkgs/desktops/gnome-3/3.22/core/caribou/default.nix
@@ -1,5 +1,5 @@
-{ fetchurl, stdenv, autoreconfHook, pkgconfig, gnome3, clutter, dbus, pythonPackages, libxml2, autoconf
-, libxklavier, libXtst, gtk2, intltool, libxslt, at_spi2_core, automake }:
+{ fetchurl, stdenv, pkgconfig, gnome3, clutter, dbus, pythonPackages, libxml2
+, libxklavier, libXtst, gtk2, intltool, libxslt, at_spi2_core, autoreconfHook }:
 
 let
   majorVersion = "0.4";
@@ -12,15 +12,14 @@ stdenv.mkDerivation rec {
     sha256 = "0mfychh1q3dx0b96pjz9a9y112bm9yqyim40yykzxx1hppsdjhww";
   };
 
+  nativeBuildInputs = [ pkgconfig autoreconfHook ];
   buildInputs = with gnome3;
-    [ glib pkgconfig gtk clutter at_spi2_core dbus pythonPackages.python automake
-      pythonPackages.pygobject3 libxml2 libXtst gtk2 intltool libxslt autoconf ];
-
-  nativeBuildInputs = [ autoreconfHook ];
+    [ glib gtk clutter at_spi2_core dbus pythonPackages.python
+      pythonPackages.pygobject3 libxml2 libXtst gtk2 intltool libxslt ];
 
   propagatedBuildInputs = [ gnome3.libgee libxklavier ];
 
-  preBuild = ''
+  postPatch = ''
     patchShebangs .
     substituteInPlace libcaribou/Makefile.am --replace "--shared-library=libcaribou.so.0" "--shared-library=$out/lib/libcaribou.so.0"
   '';
diff --git a/pkgs/development/compilers/gcc/4.8/default.nix b/pkgs/development/compilers/gcc/4.8/default.nix
index ee7ddccced7..7a41ba38e51 100644
--- a/pkgs/development/compilers/gcc/4.8/default.nix
+++ b/pkgs/development/compilers/gcc/4.8/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, noSysDirs
+{ stdenv, fetchurl, fetchpatch, noSysDirs
 , langC ? true, langCC ? true, langFortran ? false
 , langObjC ? targetPlatform.isDarwin
 , langObjCpp ? targetPlatform.isDarwin
@@ -71,7 +71,14 @@ let version = "4.8.5";
       # target libraries and tools.
       ++ optional langAda ../gnat-cflags.patch
       ++ optional langFortran ../gfortran-driving.patch
-      ++ optional hostPlatform.isDarwin ../gfortran-darwin-NXConstStr.patch;
+      ++ optional hostPlatform.isDarwin ../gfortran-darwin-NXConstStr.patch
+      ++ [(fetchpatch {
+          name = "libc_name_p.diff"; # needed to build with gcc6
+          url = "https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff_plain;h=ec1cc0263f1";
+          sha256 = "01jd7pdarh54ki498g6sz64ijl9a1l5f9v8q2696aaxalvh2vwzl";
+          excludes = [ "gcc/cp/ChangeLog" ];
+        })]
+      ;
 
     javaEcj = fetchurl {
       # The `$(top_srcdir)/ecj.jar' file is automatically picked up at
@@ -218,7 +225,7 @@ stdenv.mkDerivation ({
 
   hardeningDisable = [ "format" ];
 
-  outputs = [ "out" "lib" "doc" ];
+  outputs = [ "out" "lib" "man" "info" ];
   setOutputFlags = false;
   NIX_NO_SELF_RPATH = true;
 
diff --git a/pkgs/development/compilers/gcc/4.9/default.nix b/pkgs/development/compilers/gcc/4.9/default.nix
index 1380d36725a..e45ee0bcc6a 100644
--- a/pkgs/development/compilers/gcc/4.9/default.nix
+++ b/pkgs/development/compilers/gcc/4.9/default.nix
@@ -72,8 +72,7 @@ let version = "4.9.4";
       # target libraries and tools.
       ++ optional langAda ../gnat-cflags.patch
       ++ optional langFortran ../gfortran-driving.patch
-      # The NXConstStr.patch can be removed at 4.9.4
-      ++ optional hostPlatform.isDarwin ../gfortran-darwin-NXConstStr.patch;
+      ;
 
     javaEcj = fetchurl {
       # The `$(top_srcdir)/ecj.jar' file is automatically picked up at
diff --git a/pkgs/development/libraries/fftw/default.nix b/pkgs/development/libraries/fftw/default.nix
index d4d8c7f8aee..5cf83752aa7 100644
--- a/pkgs/development/libraries/fftw/default.nix
+++ b/pkgs/development/libraries/fftw/default.nix
@@ -4,7 +4,10 @@ with lib;
 
 assert elem precision [ "single" "double" "long-double" "quad-precision" ];
 
-let version = "3.3.6-pl1"; in
+let
+  version = "3.3.6-pl1";
+  withDoc = stdenv.cc.isGNU;
+in
 
 stdenv.mkDerivation rec {
   name = "fftw-${precision}-${version}";
@@ -14,7 +17,8 @@ stdenv.mkDerivation rec {
     sha256 = "0g8qk98lgq770ixdf7n36yd5xjsgm2v3wzvnphwmhy6r4y2amx0y";
   };
 
-  outputs = [ "out" "dev" "man" "info" ]; # it's dev-doc only
+  outputs = [ "out" "dev" "man" ]
+    ++ optional withDoc "info"; # it's dev-doc only
   outputBin = "dev"; # fftw-wisdom
 
   configureFlags =
@@ -27,7 +31,7 @@ stdenv.mkDerivation rec {
     ++ optional (stdenv.isx86_64 && (precision == "single" || precision == "double") )  "--enable-sse2"
     ++ optional stdenv.cc.isGNU "--enable-openmp"
     # doc generation causes Fortran wrapper generation which hard-codes gcc
-    ++ optional (!stdenv.cc.isGNU) "--disable-doc";
+    ++ optional (!withDoc) "--disable-doc";
 
   enableParallelBuilding = true;
 
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 2f97b8a49f1..73aba9ab34d 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -539,6 +539,8 @@ with pkgs;
 
   apt = callPackage ../tools/package-management/apt {
     inherit (perlPackages) Po4a;
+    # include/c++/6.4.0/cstdlib:75:25: fatal error: stdlib.h: No such file or directory
+    stdenv = overrideCC stdenv gcc5;
   };
 
   autorevision = callPackage ../tools/misc/autorevision { };
@@ -14971,6 +14973,8 @@ with pkgs;
     harfbuzz = harfbuzz.override {
       withIcu = true; withGraphite2 = true;
     };
+    # checking whether g++ supports C++14 or C++11... configure: error: no
+    stdenv = overrideCC stdenv gcc5;
   });
 
   libreoffice-still = lowPrio (callPackage ../applications/office/libreoffice/still.nix {
@@ -14990,6 +14994,8 @@ with pkgs;
     harfbuzz = harfbuzz.override {
       withIcu = true; withGraphite2 = true;
     };
+    # checking whether g++ supports C++14 or C++11... configure: error: no
+    stdenv = overrideCC stdenv gcc5;
   });