Merge branch 'staging' into staging-next

80 files changed, 116 insertions, 145 deletions

diff --git a/pkgs/development/libraries/argp-standalone/default.nix b/pkgs/development/libraries/argp-standalone/default.nix
index 8fe3bd287c1..6544c481187 100644
--- a/pkgs/development/libraries/argp-standalone/default.nix
+++ b/pkgs/development/libraries/argp-standalone/default.nix
@@ -31,7 +31,7 @@ stdenv.mkDerivation {
        stdenv.lib.optionals stdenv.hostPlatform.isDarwin [ patch-argp-fmtstream ]
     ++ stdenv.lib.optionals stdenv.hostPlatform.isLinux [ patch-throw-in-funcdef patch-shared ];
 
-  patchFlags = stdenv.lib.optionalString stdenv.hostPlatform.isDarwin "-p0";
+  patchFlags = stdenv.lib.optional stdenv.hostPlatform.isDarwin "-p0";
 
   preConfigure = stdenv.lib.optionalString stdenv.hostPlatform.isLinux "export CFLAGS='-fgnu89-inline'";
 
diff --git a/pkgs/development/libraries/aws-c-common/default.nix b/pkgs/development/libraries/aws-c-common/default.nix
index 4286eedc87b..b10797d3d56 100644
--- a/pkgs/development/libraries/aws-c-common/default.nix
+++ b/pkgs/development/libraries/aws-c-common/default.nix
@@ -13,10 +13,8 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ cmake ];
 
-  NIX_CFLAGS_COMPILE = lib.optionals stdenv.isDarwin [
-    "-Wno-nullability-extension"
-    "-Wno-typedef-redefinition"
-  ];
+  NIX_CFLAGS_COMPILE = lib.optionalString stdenv.isDarwin
+    "-Wno-nullability-extension -Wno-typedef-redefinition";
 
   meta = with lib; {
     description = "AWS SDK for C common core";
diff --git a/pkgs/development/libraries/bamf/default.nix b/pkgs/development/libraries/bamf/default.nix
index 1bce315878d..60322f53016 100644
--- a/pkgs/development/libraries/bamf/default.nix
+++ b/pkgs/development/libraries/bamf/default.nix
@@ -88,9 +88,7 @@ stdenv.mkDerivation rec {
   doCheck = false;
 
   # glib-2.62 deprecations
-  NIX_CFLAGS_COMPILE = [
-    "-DGLIB_DISABLE_DEPRECATION_WARNINGS"
-  ];
+  NIX_CFLAGS_COMPILE = "-DGLIB_DISABLE_DEPRECATION_WARNINGS";
 
   meta = with stdenv.lib; {
     description = "Application matching framework";
diff --git a/pkgs/development/libraries/belle-sip/default.nix b/pkgs/development/libraries/belle-sip/default.nix
index 1745614f741..0d3df37d8e0 100644
--- a/pkgs/development/libraries/belle-sip/default.nix
+++ b/pkgs/development/libraries/belle-sip/default.nix
@@ -17,7 +17,7 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ zlib ];
 
-  NIX_CFLAGS_COMPILE = [
+  NIX_CFLAGS_COMPILE = toString [
     "-Wno-error=deprecated-declarations"
     "-Wno-error=format-truncation"
     "-Wno-error=cast-function-type"
diff --git a/pkgs/development/libraries/buddy/default.nix b/pkgs/development/libraries/buddy/default.nix
index fb25b0a5810..9b722602a65 100644
--- a/pkgs/development/libraries/buddy/default.nix
+++ b/pkgs/development/libraries/buddy/default.nix
@@ -11,9 +11,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ bison ];
   patches = [ ./gcc-4.3.3-fixes.patch ];
   configureFlags = [ "CFLAGS=-O3" "CXXFLAGS=-O3" ];
-  NIX_LDFLAGS = [
-    "-lm"
-  ];
+  NIX_LDFLAGS = "-lm";
   doCheck = true;
 
   meta = {
diff --git a/pkgs/development/libraries/cpp-hocon/default.nix b/pkgs/development/libraries/cpp-hocon/default.nix
index d172ab55fa3..dc742a5c051 100644
--- a/pkgs/development/libraries/cpp-hocon/default.nix
+++ b/pkgs/development/libraries/cpp-hocon/default.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
     owner = "puppetlabs";
   };
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error=catch-value" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error=catch-value";
 
   nativeBuildInputs = [ cmake ];
 
diff --git a/pkgs/development/libraries/cppdb/default.nix b/pkgs/development/libraries/cppdb/default.nix
index a21b3cc93fa..bb521ba3ec0 100644
--- a/pkgs/development/libraries/cppdb/default.nix
+++ b/pkgs/development/libraries/cppdb/default.nix
@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ cmake sqlite libmysqlclient postgresql unixODBC ];
 
   cmakeFlags = [ "--no-warn-unused-cli" ];
-  NIX_CFLAGS_COMPILE = [ "-I${libmysqlclient}/include/mysql" "-L${libmysqlclient}/lib/mysql" ];
+  NIX_CFLAGS_COMPILE = "-I${libmysqlclient}/include/mysql -L${libmysqlclient}/lib/mysql";
 
   meta = with stdenv.lib; {
     homepage = http://cppcms.com/sql/cppdb/;
diff --git a/pkgs/development/libraries/crc32c/default.nix b/pkgs/development/libraries/crc32c/default.nix
index 916ec5b703b..a7313c20553 100644
--- a/pkgs/development/libraries/crc32c/default.nix
+++ b/pkgs/development/libraries/crc32c/default.nix
@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ cmake ];
   buildInputs = [ gflags ];
-  NIX_CFLAGS_COMPILE = stdenv.lib.optional stdenv.isAarch64 "-march=armv8-a+crc";
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isAarch64 "-march=armv8-a+crc";
 
   meta = with stdenv.lib; {
     homepage = https://github.com/google/crc32c;
diff --git a/pkgs/development/libraries/crypto++/default.nix b/pkgs/development/libraries/crypto++/default.nix
index b472733f8ee..3fe27748155 100644
--- a/pkgs/development/libraries/crypto++/default.nix
+++ b/pkgs/development/libraries/crypto++/default.nix
@@ -29,7 +29,7 @@ stdenv.mkDerivation rec {
   doCheck = true;
 
   preInstall = "rm libcryptopp.a"; # built for checks but we don't install static lib into the nix store
-  installTargets = "install-lib";
+  installTargets = [ "install-lib" ];
   installFlags = [ "LDCONF=true" ];
   postInstall = optionalString (!stdenv.hostPlatform.isDarwin) ''
     ln -sr $out/lib/libcryptopp.so.${version} $out/lib/libcryptopp.so.${versions.majorMinor version}
diff --git a/pkgs/development/libraries/cwiid/default.nix b/pkgs/development/libraries/cwiid/default.nix
index 246dd009820..d9a17aff941 100644
--- a/pkgs/development/libraries/cwiid/default.nix
+++ b/pkgs/development/libraries/cwiid/default.nix
@@ -23,9 +23,7 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ autoreconfHook pkgconfig ];
 
-  NIX_LDFLAGS = [
-    "-lbluetooth"
-  ];
+  NIX_LDFLAGS = "-lbluetooth";
 
   postInstall = ''
     # Some programs (for example, cabal-install) have problems with the double 0
diff --git a/pkgs/development/libraries/ffmpeg/generic.nix b/pkgs/development/libraries/ffmpeg/generic.nix
index 3424493c209..956d2d7223f 100644
--- a/pkgs/development/libraries/ffmpeg/generic.nix
+++ b/pkgs/development/libraries/ffmpeg/generic.nix
@@ -44,7 +44,7 @@
 
 let
   inherit (stdenv) isDarwin isFreeBSD isLinux isAarch32;
-  inherit (stdenv.lib) optional optionals optionalString enableFeature;
+  inherit (stdenv.lib) optional optionals optionalString enableFeature filter;
 
   cmpVer = builtins.compareVersions;
   reqMin = requiredVersion: (cmpVer requiredVersion branch != 1);
@@ -85,7 +85,7 @@ stdenv.mkDerivation rec {
   setOutputFlags = false; # doesn't accept all and stores configureFlags in libs!
 
   configurePlatforms = [];
-  configureFlags = [
+  configureFlags = filter (v: v != null) ([
       "--arch=${stdenv.hostPlatform.parsed.cpu.name}"
       "--target_os=${stdenv.hostPlatform.parsed.kernel.name}"
     # License
@@ -96,13 +96,15 @@ stdenv.mkDerivation rec {
       (ifMinVer "0.6" "--enable-pic")
       (enableFeature runtimeCpuDetectBuild "runtime-cpudetect")
       "--enable-hardcoded-tables"
+    ] ++
       (if multithreadBuild then (
          if stdenv.isCygwin then
-           "--disable-pthreads --enable-w32threads"
+           ["--disable-pthreads" "--enable-w32threads"]
          else # Use POSIX threads by default
-           "--enable-pthreads --disable-w32threads")
+           ["--enable-pthreads" "--disable-w32threads"])
        else
-         "--disable-pthreads --disable-w32threads")
+         ["--disable-pthreads" "--disable-w32threads"])
+    ++ [
       (ifMinVer "0.9" "--disable-os2threads") # We don't support OS/2
       "--enable-network"
       (ifMinVer "2.4" "--enable-pixelutils")
@@ -161,7 +163,7 @@ stdenv.mkDerivation rec {
   ] ++ optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
       "--cross-prefix=${stdenv.cc.targetPrefix}"
       "--enable-cross-compile"
-  ] ++ optional stdenv.cc.isClang "--cc=clang";
+  ] ++ optional stdenv.cc.isClang "--cc=clang");
 
   nativeBuildInputs = [ addOpenGLRunpath perl pkgconfig texinfo yasm ];
 
diff --git a/pkgs/development/libraries/flatpak/default.nix b/pkgs/development/libraries/flatpak/default.nix
index 945f1d4931f..c0a3d3718f3 100644
--- a/pkgs/development/libraries/flatpak/default.nix
+++ b/pkgs/development/libraries/flatpak/default.nix
@@ -52,9 +52,7 @@ stdenv.mkDerivation rec {
 
   doCheck = false; # TODO: some issues with temporary files
 
-  NIX_LDFLAGS = [
-    "-lpthread"
-  ];
+  NIX_LDFLAGS = "-lpthread";
 
   enableParallelBuilding = true;
 
diff --git a/pkgs/development/libraries/flint/default.nix b/pkgs/development/libraries/flint/default.nix
index 20a80119b13..462d186c72d 100644
--- a/pkgs/development/libraries/flint/default.nix
+++ b/pkgs/development/libraries/flint/default.nix
@@ -39,7 +39,7 @@ stdenv.mkDerivation rec {
   ];
 
   # issues with ntl -- https://github.com/wbhart/flint2/issues/487
-  NIX_CXXSTDLIB_COMPILE = [ "-std=c++11" ];
+  NIX_CXXSTDLIB_COMPILE = "-std=c++11";
 
   patches = [
     (fetchpatch {
diff --git a/pkgs/development/libraries/gdal/gdal-1_11.nix b/pkgs/development/libraries/gdal/gdal-1_11.nix
index a6574053414..6a086d9c998 100644
--- a/pkgs/development/libraries/gdal/gdal-1_11.nix
+++ b/pkgs/development/libraries/gdal/gdal-1_11.nix
@@ -40,9 +40,7 @@ stdenv.mkDerivation rec {
   ];
 
   # Allow use of old proj_api.h
-  NIX_CFLAGS_COMPILE = [
-    "-DACCEPT_USE_OF_DEPRECATED_PROJ_API_H=1"
-  ];
+  NIX_CFLAGS_COMPILE = "-DACCEPT_USE_OF_DEPRECATED_PROJ_API_H=1";
 
   # Prevent this:
   #
diff --git a/pkgs/development/libraries/gdbm/default.nix b/pkgs/development/libraries/gdbm/default.nix
index 972e9022235..830a311db70 100644
--- a/pkgs/development/libraries/gdbm/default.nix
+++ b/pkgs/development/libraries/gdbm/default.nix
@@ -4,9 +4,6 @@ stdenv.mkDerivation rec {
   pname = "gdbm";
   version = "1.18.1";
 
-  # FIXME: remove on update to > 1.18.1
-  NIX_CFLAGS_COMPILE = if stdenv.cc.isClang then "-Wno-error=return-type" else null;
-
   src = fetchurl {
     url = "mirror://gnu/gdbm/${pname}-${version}.tar.gz";
     sha256 = "1p4ibds6z3ccy65lkmd6lm7js0kwifvl53r0fd759fjxgr917rl6";
diff --git a/pkgs/development/libraries/gegl/4.0.nix b/pkgs/development/libraries/gegl/4.0.nix
index 1bdf557f399..75897b036bf 100644
--- a/pkgs/development/libraries/gegl/4.0.nix
+++ b/pkgs/development/libraries/gegl/4.0.nix
@@ -118,7 +118,7 @@ stdenv.mkDerivation rec {
 
   # TODO: Fix missing math symbols in gegl seamless clone.
   # It only appears when we use packaged poly2tri-c instead of vendored one.
-  NIX_CFLAGS_COMPILE = [ "-lm" ];
+  NIX_CFLAGS_COMPILE = "-lm";
 
   postPatch = ''
     chmod +x tests/opencl/opencl_test.sh tests/buffer/buffer-tests-run.sh
diff --git a/pkgs/development/libraries/geis/default.nix b/pkgs/development/libraries/geis/default.nix
index 97b9ba087e2..1b3d5ba4b7c 100644
--- a/pkgs/development/libraries/geis/default.nix
+++ b/pkgs/development/libraries/geis/default.nix
@@ -29,7 +29,7 @@ stdenv.mkDerivation rec {
     sha256 = "1svhbjibm448ybq6gnjjzj0ak42srhihssafj0w402aj71lgaq4a";
   };
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error=misleading-indentation" "-Wno-error=pointer-compare" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error=misleading-indentation -Wno-error=pointer-compare";
 
   hardeningDisable = [ "format" ];
 
diff --git a/pkgs/development/libraries/glib/default.nix b/pkgs/development/libraries/glib/default.nix
index 67d3c35609e..0febed9f9c9 100644
--- a/pkgs/development/libraries/glib/default.nix
+++ b/pkgs/development/libraries/glib/default.nix
@@ -118,7 +118,7 @@ stdenv.mkDerivation rec {
     "-Ddevbindir=${placeholder ''dev''}/bin"
   ];
 
-  NIX_CFLAGS_COMPILE = [
+  NIX_CFLAGS_COMPILE = toString [
     "-Wno-error=nonnull"
     # Default for release buildtype but passed manually because
     # we're using plain
diff --git a/pkgs/development/libraries/glm/default.nix b/pkgs/development/libraries/glm/default.nix
index 88b33601ee7..d39d6f0d7a3 100644
--- a/pkgs/development/libraries/glm/default.nix
+++ b/pkgs/development/libraries/glm/default.nix
@@ -27,9 +27,7 @@ stdenv.mkDerivation rec {
     cp ${gcc7PlatformPatch} glm/simd/platform.h
   '';
 
-  NIX_CFLAGS_COMPILE = stdenv.lib.optionals stdenv.isDarwin [
-    "-DGLM_COMPILER=0"
-  ];
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isDarwin "-DGLM_COMPILER=0";
 
   postInstall = ''
     mkdir -p $doc/share/doc/glm
diff --git a/pkgs/development/libraries/gperftools/default.nix b/pkgs/development/libraries/gperftools/default.nix
index bc10c9f9bdd..0e985754985 100644
--- a/pkgs/development/libraries/gperftools/default.nix
+++ b/pkgs/development/libraries/gperftools/default.nix
@@ -16,9 +16,8 @@ stdenv.mkDerivation rec {
     substituteInPlace libtool --replace stdc++ c++
   '';
 
-  NIX_CFLAGS_COMPILE = stdenv.lib.optionals stdenv.isDarwin [
-    "-D_XOPEN_SOURCE" "-Wno-aligned-allocation-unavailable"
-  ];
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isDarwin
+    "-D_XOPEN_SOURCE -Wno-aligned-allocation-unavailable";
 
   # some packages want to link to the static tcmalloc_minimal
   # to drop the runtime dependency on gperftools
diff --git a/pkgs/development/libraries/gpgme/default.nix b/pkgs/development/libraries/gpgme/default.nix
index 63072273c2e..ed2b5563bd3 100644
--- a/pkgs/development/libraries/gpgme/default.nix
+++ b/pkgs/development/libraries/gpgme/default.nix
@@ -47,12 +47,12 @@ stdenv.mkDerivation rec {
   # fit in the limit. https://github.com/NixOS/nix/pull/1085
     ++ lib.optionals stdenv.isDarwin [ "--disable-gpg-test" ];
 
-  NIX_CFLAGS_COMPILE =
+  NIX_CFLAGS_COMPILE = toString (
     # qgpgme uses Q_ASSERT which retains build inputs at runtime unless
     # debugging is disabled
     lib.optional (qtbase != null) "-DQT_NO_DEBUG"
     # https://www.gnupg.org/documentation/manuals/gpgme/Largefile-Support-_0028LFS_0029.html
-    ++ lib.optional (system == "i686-linux") "-D_FILE_OFFSET_BITS=64";
+    ++ lib.optional (system == "i686-linux") "-D_FILE_OFFSET_BITS=64");
 
   checkInputs = [ which ];
 
diff --git a/pkgs/development/libraries/gsl/default.nix b/pkgs/development/libraries/gsl/default.nix
index 1fd086ca23c..966d6a8ffd5 100644
--- a/pkgs/development/libraries/gsl/default.nix
+++ b/pkgs/development/libraries/gsl/default.nix
@@ -9,7 +9,7 @@ stdenv.mkDerivation rec {
   };
 
   # do not let -march=skylake to enable FMA (https://lists.gnu.org/archive/html/bug-gsl/2011-11/msg00019.html)
-  NIX_CFLAGS_COMPILE = stdenv.lib.optional stdenv.isx86_64 "-mno-fma";
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isx86_64 "-mno-fma";
 
   # https://lists.gnu.org/archive/html/bug-gsl/2015-11/msg00012.html
   doCheck = stdenv.hostPlatform.system != "i686-linux" && stdenv.hostPlatform.system != "aarch64-linux";
diff --git a/pkgs/development/libraries/gsl/gsl-1_16.nix b/pkgs/development/libraries/gsl/gsl-1_16.nix
index e5772c8772e..ae102ac6030 100644
--- a/pkgs/development/libraries/gsl/gsl-1_16.nix
+++ b/pkgs/development/libraries/gsl/gsl-1_16.nix
@@ -9,7 +9,7 @@ stdenv.mkDerivation rec {
   };
 
   # do not let -march=skylake to enable FMA (https://lists.gnu.org/archive/html/bug-gsl/2011-11/msg00019.html)
-  NIX_CFLAGS_COMPILE = stdenv.lib.optional stdenv.isx86_64 "-mno-fma";
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isx86_64 "-mno-fma";
 
   patches = [
     (fetchpatch {
diff --git a/pkgs/development/libraries/gtk/2.x.nix b/pkgs/development/libraries/gtk/2.x.nix
index 4286d6a73fb..932527eed09 100644
--- a/pkgs/development/libraries/gtk/2.x.nix
+++ b/pkgs/development/libraries/gtk/2.x.nix
@@ -30,7 +30,7 @@ stdenv.mkDerivation rec {
     ./hooks/drop-icon-theme-cache.sh
   ];
 
-  nativeBuildInputs = [ setupHooks perl pkgconfig gettext gobject-introspection ];
+  nativeBuildInputs = setupHooks ++ [ perl pkgconfig gettext gobject-introspection ];
 
   patches = [
     ./patches/2.0-immodules.cache.patch
diff --git a/pkgs/development/libraries/gtk/3.x.nix b/pkgs/development/libraries/gtk/3.x.nix
index 7f09b52d51f..60432614433 100644
--- a/pkgs/development/libraries/gtk/3.x.nix
+++ b/pkgs/development/libraries/gtk/3.x.nix
@@ -88,10 +88,7 @@ stdenv.mkDerivation rec {
 
   # These are the defines that'd you'd get with --enable-debug=minimum (default).
   # See: https://developer.gnome.org/gtk3/stable/gtk-building.html#extra-configuration-options
-  NIX_CFLAGS_COMPILE = [
-    "-DG_ENABLE_DEBUG"
-    "-DG_DISABLE_CAST_CHECKS"
-  ];
+  NIX_CFLAGS_COMPILE = "-DG_ENABLE_DEBUG -DG_DISABLE_CAST_CHECKS";
 
   postPatch = ''
     files=(
@@ -118,8 +115,7 @@ stdenv.mkDerivation rec {
     pkgconfig
     python3
     sassc
-    setupHooks
-  ] ++ optionals withGtkDoc [
+  ] ++ setupHooks ++ optionals withGtkDoc [
     docbook_xml_dtd_43
     docbook_xsl
     gtk-doc
diff --git a/pkgs/development/libraries/hspell/dicts.nix b/pkgs/development/libraries/hspell/dicts.nix
index 637a11efaef..83942c2c1dd 100644
--- a/pkgs/development/libraries/hspell/dicts.nix
+++ b/pkgs/development/libraries/hspell/dicts.nix
@@ -3,12 +3,11 @@
 let
   dict = variant: a: stdenv.mkDerivation ({
     inherit (hspell) src patchPhase nativeBuildInputs;
+    buildFlags = [ variant ];
+
     meta = hspell.meta // {
       broken = true;
       description = "${variant} Hebrew dictionary";
-
-      buildFlags = [ variant ];
-
     } // (if a ? meta then a.meta else {});
   } // (removeAttrs a ["meta"]));
 in
diff --git a/pkgs/development/libraries/ilmbase/default.nix b/pkgs/development/libraries/ilmbase/default.nix
index a25a590b370..00cdda1e570 100644
--- a/pkgs/development/libraries/ilmbase/default.nix
+++ b/pkgs/development/libraries/ilmbase/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
   depsBuildBuild = [ buildPackages.stdenv.cc ];
   nativeBuildInputs = [ automake autoconf libtool which ];
 
-  NIX_CFLAGS_LINK = [ "-pthread" ];
+  NIX_CFLAGS_LINK = "-pthread";
 
   patches = [
     ./bootstrap.patch
diff --git a/pkgs/development/libraries/java/swt/default.nix b/pkgs/development/libraries/java/swt/default.nix
index 6eb5a1f5355..b0fdca11218 100644
--- a/pkgs/development/libraries/java/swt/default.nix
+++ b/pkgs/development/libraries/java/swt/default.nix
@@ -38,8 +38,8 @@ in stdenv.mkDerivation rec {
   nativeBuildInputs = [ unzip pkgconfig ];
   buildInputs = [ jdk gtk2 libXt libXtst libXi libGLU libGL webkitgtk libsoup ];
 
-  NIX_LFLAGS = (map (x: "-L${lib.getLib x}/lib") [ xorg.libX11 pango gdk-pixbuf glib ]) ++
-    [ "-lX11" "-lpango-1.0" "-lgdk_pixbuf-2.0" "-lglib-2.0" ];
+  NIX_LFLAGS = toString (map (x: "-L${lib.getLib x}/lib") [ xorg.libX11 pango gdk-pixbuf glib ]) +
+    " -lX11 -lpango-1.0 -lgdk_pixbuf-2.0 -lglib-2.0";
 
   buildPhase = ''
     unzip src.zip -d src
diff --git a/pkgs/development/libraries/leatherman/default.nix b/pkgs/development/libraries/leatherman/default.nix
index 44c393baf8e..b7b9b019b63 100644
--- a/pkgs/development/libraries/leatherman/default.nix
+++ b/pkgs/development/libraries/leatherman/default.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
     owner = "puppetlabs";
   };
 
-  NIX_CFLAGS_COMPILE = [
+  NIX_CFLAGS_COMPILE = builtins.toString [
     "-Wno-error=ignored-qualifiers"
     "-Wno-error=class-memaccess"
     "-Wno-error=catch-value"
diff --git a/pkgs/development/libraries/libbluray/default.nix b/pkgs/development/libraries/libbluray/default.nix
index 517251e137e..daa349ca630 100644
--- a/pkgs/development/libraries/libbluray/default.nix
+++ b/pkgs/development/libraries/libbluray/default.nix
@@ -40,7 +40,7 @@ stdenv.mkDerivation rec {
 
   propagatedBuildInputs = optional withAACS libaacs;
 
-  NIX_LDFLAGS = [
+  NIX_LDFLAGS = toString [
     (optionalString withAACS   "-L${libaacs}/lib -laacs")
     (optionalString withBDplus "-L${libbdplus}/lib -lbdplus")
   ];
diff --git a/pkgs/development/libraries/libcaca/default.nix b/pkgs/development/libraries/libcaca/default.nix
index 8949ea8e390..7773fe46c0c 100644
--- a/pkgs/development/libraries/libcaca/default.nix
+++ b/pkgs/development/libraries/libcaca/default.nix
@@ -19,12 +19,12 @@ stdenv.mkDerivation rec {
     (if x11Support then "--enable-x11" else "--disable-x11")
     ];
 
-  NIX_CFLAGS_COMPILE = stdenv.lib.optional (!x11Support) "-DX_DISPLAY_MISSING";
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString (!x11Support) "-DX_DISPLAY_MISSING";
 
   enableParallelBuilding = true;
 
   propagatedBuildInputs = [ ncurses zlib pkgconfig (imlib2.override { inherit x11Support; }) ]
-    ++ stdenv.lib.optionals x11Support [ libX11 libXext];
+    ++ stdenv.lib.optionals x11Support [ libX11 libXext ];
 
   postInstall = ''
     mkdir -p $dev/bin
diff --git a/pkgs/development/libraries/libcbor/default.nix b/pkgs/development/libraries/libcbor/default.nix
index 4d56c0f1403..4949d657669 100644
--- a/pkgs/development/libraries/libcbor/default.nix
+++ b/pkgs/development/libraries/libcbor/default.nix
@@ -16,7 +16,7 @@ stdenv.mkDerivation rec {
 
   doCheck = false; # needs "-DWITH_TESTS=ON", but fails w/compilation error
 
-  NIX_CFLAGS_COMPILE = [ "-fno-lto" ];
+  NIX_CFLAGS_COMPILE = "-fno-lto";
 
   meta = with stdenv.lib; {
     description = "CBOR protocol implementation for C and others";
diff --git a/pkgs/development/libraries/libdynd/default.nix b/pkgs/development/libraries/libdynd/default.nix
index bc492815339..c02a6f9a502 100644
--- a/pkgs/development/libraries/libdynd/default.nix
+++ b/pkgs/development/libraries/libdynd/default.nix
@@ -17,7 +17,7 @@ stdenv.mkDerivation {
   ];
 
   # added to fix build with gcc7+
-  NIX_CFLAGS_COMPILE = [
+  NIX_CFLAGS_COMPILE = builtins.toString [
     "-Wno-error=implicit-fallthrough"
     "-Wno-error=nonnull"
     "-Wno-error=tautological-compare"
diff --git a/pkgs/development/libraries/libfakekey/default.nix b/pkgs/development/libraries/libfakekey/default.nix
index 196f0e50bef..3c243191543 100644
--- a/pkgs/development/libraries/libfakekey/default.nix
+++ b/pkgs/development/libraries/libfakekey/default.nix
@@ -11,9 +11,7 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ pkgconfig ];
   buildInputs = [ libX11 libXi libXtst xorgproto ];
-  NIX_LDFLAGS = [
-    "-lX11"
-  ];
+  NIX_LDFLAGS = "-lX11";
 
   meta = with stdenv.lib; {
     description = "X virtual keyboard library";
diff --git a/pkgs/development/libraries/libfpx/default.nix b/pkgs/development/libraries/libfpx/default.nix
index f4863eb33f2..97df5107409 100644
--- a/pkgs/development/libraries/libfpx/default.nix
+++ b/pkgs/development/libraries/libfpx/default.nix
@@ -9,7 +9,7 @@ stdenv.mkDerivation rec {
   };
 
   # Darwin gets misdetected as Windows without this
-  NIX_CFLAGS_COMPILE = if stdenv.isDarwin then "-D__unix" else null;
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isDarwin "-D__unix";
 
   patches = [
     (fetchpatch {
diff --git a/pkgs/development/libraries/libftdi/default.nix b/pkgs/development/libraries/libftdi/default.nix
index 08ec1d84a3f..3dffbd075e9 100644
--- a/pkgs/development/libraries/libftdi/default.nix
+++ b/pkgs/development/libraries/libftdi/default.nix
@@ -14,7 +14,7 @@ with stdenv; mkDerivation rec {
 
   # Hack to avoid TMPDIR in RPATHs.
   preFixup = ''rm -rf "$(pwd)" '';
-  configureFlags = lib.optional (!isDarwin) [ "--with-async-mode" ];
+  configureFlags = lib.optional (!isDarwin) "--with-async-mode";
 
   # allow async mode. from ubuntu. see:
   #   https://bazaar.launchpad.net/~ubuntu-branches/ubuntu/trusty/libftdi/trusty/view/head:/debian/patches/04_async_mode.diff
diff --git a/pkgs/development/libraries/libgdiplus/default.nix b/pkgs/development/libraries/libgdiplus/default.nix
index 1a690ca7aa1..54bf091e5ea 100644
--- a/pkgs/development/libraries/libgdiplus/default.nix
+++ b/pkgs/development/libraries/libgdiplus/default.nix
@@ -21,7 +21,7 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ autoreconfHook pkgconfig ];
 
-  configureFlags = stdenv.lib.optionalString stdenv.cc.isClang "--host=${stdenv.hostPlatform.system}";
+  configureFlags = stdenv.lib.optional stdenv.cc.isClang "--host=${stdenv.hostPlatform.system}";
 
   buildInputs =
     [ glib cairo fontconfig libtiff giflib
diff --git a/pkgs/development/libraries/libglvnd/default.nix b/pkgs/development/libraries/libglvnd/default.nix
index c2a5cfbed74..55b801b0b0d 100644
--- a/pkgs/development/libraries/libglvnd/default.nix
+++ b/pkgs/development/libraries/libglvnd/default.nix
@@ -39,13 +39,13 @@ stdenv.mkDerivation rec {
       --replace "-Xlinker --version-script=$(VERSION_SCRIPT)" "-Xlinker"
   '';
 
-  NIX_CFLAGS_COMPILE = [
+  NIX_CFLAGS_COMPILE = toString ([
     "-UDEFAULT_EGL_VENDOR_CONFIG_DIRS"
     # FHS paths are added so that non-NixOS applications can find vendor files.
     "-DDEFAULT_EGL_VENDOR_CONFIG_DIRS=\"${addOpenGLRunpath.driverLink}/share/glvnd/egl_vendor.d:/etc/glvnd/egl_vendor.d:/usr/share/glvnd/egl_vendor.d\""
 
     "-Wno-error=array-bounds"
-  ] ++ lib.optional stdenv.cc.isClang "-Wno-error";
+  ] ++ lib.optional stdenv.cc.isClang "-Wno-error");
 
   # Indirectly: https://bugs.freedesktop.org/show_bug.cgi?id=35268
   configureFlags  = stdenv.lib.optional stdenv.hostPlatform.isMusl "--disable-tls";
diff --git a/pkgs/development/libraries/libjpeg-drop/default.nix b/pkgs/development/libraries/libjpeg-drop/default.nix
index 4e9c165e71f..8ed1c9bf92f 100644
--- a/pkgs/development/libraries/libjpeg-drop/default.nix
+++ b/pkgs/development/libraries/libjpeg-drop/default.nix
@@ -24,7 +24,7 @@ stdenv.mkDerivation {
   '';
 
   configureFlags = []
-    ++ optional static [ "--enable-static" "--disable-shared" ];
+    ++ optionals static [ "--enable-static" "--disable-shared" ];
 
   outputs = [ "bin" "dev" "out" "man" ];
 
diff --git a/pkgs/development/libraries/libmatchbox/default.nix b/pkgs/development/libraries/libmatchbox/default.nix
index 3786c5e77d3..98875e48f57 100644
--- a/pkgs/development/libraries/libmatchbox/default.nix
+++ b/pkgs/development/libraries/libmatchbox/default.nix
@@ -6,9 +6,7 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ libXft libICE pango libjpeg ];
   propagatedBuildInputs = [ libX11 libXext libpng ];
-  NIX_LDFLAGS = [
-    "-lX11"
-  ];
+  NIX_LDFLAGS = "-lX11";
 
   src = fetchurl {
     url = "https://downloads.yoctoproject.org/releases/matchbox/libmatchbox/${version}/libmatchbox-${version}.tar.bz2";
diff --git a/pkgs/development/libraries/libmemcached/default.nix b/pkgs/development/libraries/libmemcached/default.nix
index 57053103417..5655bfe968b 100644
--- a/pkgs/development/libraries/libmemcached/default.nix
+++ b/pkgs/development/libraries/libmemcached/default.nix
@@ -23,7 +23,7 @@ stdenv.mkDerivation {
   buildInputs = [ libevent ];
   propagatedBuildInputs = [ cyrus_sasl ];
 
-  NIX_CFLAGS_COMPILE = [ "-fpermissive"/*gcc7*/ ];
+  NIX_CFLAGS_COMPILE = "-fpermissive";
 
   meta = with stdenv.lib; {
     homepage = https://libmemcached.org;
diff --git a/pkgs/development/libraries/liboping/default.nix b/pkgs/development/libraries/liboping/default.nix
index ff8f200a3bb..b2594d7c1d7 100644
--- a/pkgs/development/libraries/liboping/default.nix
+++ b/pkgs/development/libraries/liboping/default.nix
@@ -8,7 +8,7 @@ stdenv.mkDerivation rec {
     sha256 = "1n2wkmvw6n80ybdwkjq8ka43z2x8mvxq49byv61b52iyz69slf7b";
   };
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error=format-truncation" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error=format-truncation";
 
   buildInputs = [ ncurses perl ];
 
diff --git a/pkgs/development/libraries/libpfm/default.nix b/pkgs/development/libraries/libpfm/default.nix
index f48c605dafd..3398d3feb94 100644
--- a/pkgs/development/libraries/libpfm/default.nix
+++ b/pkgs/development/libraries/libpfm/default.nix
@@ -16,7 +16,7 @@ stdenv.mkDerivation (rec {
     "SYS=${stdenv.hostPlatform.uname.system}"
   ];
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error";
 
   meta = with stdenv.lib; {
     description = "Helper library to program the performance monitoring events";
diff --git a/pkgs/development/libraries/libqtav/default.nix b/pkgs/development/libraries/libqtav/default.nix
index 22245f5fa2a..dd6318444e7 100644
--- a/pkgs/development/libraries/libqtav/default.nix
+++ b/pkgs/development/libraries/libqtav/default.nix
@@ -30,7 +30,7 @@ mkDerivation rec {
   # Make sure libqtav finds its libGL dependency at both link and run time
   # by adding libGL to rpath. Not sure why it wasn't done automatically like
   # the other libraries as `libGL` is part of our `buildInputs`.
-  NIX_CFLAGS_LINK = [ "-Wl,-rpath,${libGL}/lib"];
+  NIX_CFLAGS_LINK = "-Wl,-rpath,${libGL}/lib";
 
   preFixup = ''
     mkdir -p "$out/bin"
diff --git a/pkgs/development/libraries/libscrypt/default.nix b/pkgs/development/libraries/libscrypt/default.nix
index b9ae1f829a1..3083136526b 100644
--- a/pkgs/development/libraries/libscrypt/default.nix
+++ b/pkgs/development/libraries/libscrypt/default.nix
@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
   buildFlags = stdenv.lib.optional stdenv.isDarwin "LDFLAGS= CFLAGS_EXTRA=";
 
   installFlags = [ "PREFIX=$(out)" ];
-  installTargets = if stdenv.isDarwin then "install-osx" else "install";
+  installTargets = stdenv.lib.optional stdenv.isDarwin "install-osx";
 
   doCheck = true;
 
diff --git a/pkgs/development/libraries/libunique/default.nix b/pkgs/development/libraries/libunique/default.nix
index e0022411221..d6566978a6b 100644
--- a/pkgs/development/libraries/libunique/default.nix
+++ b/pkgs/development/libraries/libunique/default.nix
@@ -10,7 +10,7 @@ stdenv.mkDerivation rec {
   };
 
   # glib-2.62 deprecations
-  NIX_CFLAGS_COMPILE = [ "-DGLIB_DISABLE_DEPRECATION_WARNINGS" ];
+  NIX_CFLAGS_COMPILE = "-DGLIB_DISABLE_DEPRECATION_WARNINGS";
 
   # Patches from Gentoo portage
   patches = [
diff --git a/pkgs/development/libraries/libvdpau/default.nix b/pkgs/development/libraries/libvdpau/default.nix
index 792a31bcf9f..e6a57f1e38c 100644
--- a/pkgs/development/libraries/libvdpau/default.nix
+++ b/pkgs/development/libraries/libvdpau/default.nix
@@ -19,7 +19,7 @@ stdenv.mkDerivation rec {
   configureFlags = stdenv.lib.optional stdenv.isLinux
     "--with-module-dir=${mesa.drivers.driverLink}/lib/vdpau";
 
-  NIX_LDFLAGS = if stdenv.isDarwin then "-lX11" else null;
+  NIX_LDFLAGS = stdenv.lib.optionalString stdenv.isDarwin "-lX11";
 
   installFlags = [ "moduledir=$(out)/lib/vdpau" ];
 
diff --git a/pkgs/development/libraries/libwhereami/default.nix b/pkgs/development/libraries/libwhereami/default.nix
index 84bd1847faa..8e190f998d5 100644
--- a/pkgs/development/libraries/libwhereami/default.nix
+++ b/pkgs/development/libraries/libwhereami/default.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
     owner = "puppetlabs";
   };
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error=catch-value" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error=catch-value";
 
   nativeBuildInputs = [ cmake ];
 
diff --git a/pkgs/development/libraries/libwps/default.nix b/pkgs/development/libraries/libwps/default.nix
index e8f39754885..61b777a5243 100644
--- a/pkgs/development/libraries/libwps/default.nix
+++ b/pkgs/development/libraries/libwps/default.nix
@@ -12,7 +12,7 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ pkgconfig ];
   buildInputs = [ boost librevenge zlib ];
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error=implicit-fallthrough" ]; # newly detected by gcc-7
+  NIX_CFLAGS_COMPILE = "-Wno-error=implicit-fallthrough";
 
   meta = with stdenv.lib; {
     homepage = http://libwps.sourceforge.net/;
diff --git a/pkgs/development/libraries/mediastreamer/default.nix b/pkgs/development/libraries/mediastreamer/default.nix
index ca62391e781..0204223d127 100644
--- a/pkgs/development/libraries/mediastreamer/default.nix
+++ b/pkgs/development/libraries/mediastreamer/default.nix
@@ -32,7 +32,7 @@ stdenv.mkDerivation rec {
     ortp libv4l libpcap srtp bctoolbox libXext libmatroska
   ];
 
-  NIX_CFLAGS_COMPILE = [
+  NIX_CFLAGS_COMPILE = toString [
     "-DGIT_VERSION=\"v${version}\""
     "-Wno-error=deprecated-declarations"
     "-Wno-error=cast-function-type"
diff --git a/pkgs/development/libraries/mlt/qt-5.nix b/pkgs/development/libraries/mlt/qt-5.nix
index f017e4452a6..0e3750df415 100644
--- a/pkgs/development/libraries/mlt/qt-5.nix
+++ b/pkgs/development/libraries/mlt/qt-5.nix
@@ -33,7 +33,7 @@ stdenv.mkDerivation rec {
 
   # mlt is unable to cope with our multi-prefix Qt build
   # because it does not use CMake or qmake.
-  NIX_CFLAGS_COMPILE = [ "-I${getDev qtsvg}/include/QtSvg" ];
+  NIX_CFLAGS_COMPILE = "-I${getDev qtsvg}/include/QtSvg";
 
   CXXFLAGS = "-std=c++11";
 
diff --git a/pkgs/development/libraries/mps/default.nix b/pkgs/development/libraries/mps/default.nix
index ec3b4e20147..8c1f3aea466 100644
--- a/pkgs/development/libraries/mps/default.nix
+++ b/pkgs/development/libraries/mps/default.nix
@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ sqlite ];
 
   # needed for 1.116.0 to build with gcc7
-  NIX_CFLAGS_COMPILE = [
+  NIX_CFLAGS_COMPILE = toString [
     "-Wno-implicit-fallthrough"
     "-Wno-error=clobbered"
     "-Wno-error=cast-function-type"
diff --git a/pkgs/development/libraries/ntrack/default.nix b/pkgs/development/libraries/ntrack/default.nix
index b79f940affa..803906b1343 100644
--- a/pkgs/development/libraries/ntrack/default.nix
+++ b/pkgs/development/libraries/ntrack/default.nix
@@ -18,7 +18,7 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ pkgconfig python ];
 
   # error: ISO C does not support '__FUNCTION__' predefined identifier [-Werror=pedantic]
-  NIX_CFLAGS_COMPILE = [ "-Wno-error" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error";
 
   configureFlags = [ "--without-gobject" "CFLAGS=--std=gnu99" ];
 
diff --git a/pkgs/development/libraries/openal-soft/default.nix b/pkgs/development/libraries/openal-soft/default.nix
index 76f2861428d..20528ac9284 100644
--- a/pkgs/development/libraries/openal-soft/default.nix
+++ b/pkgs/development/libraries/openal-soft/default.nix
@@ -35,9 +35,9 @@ stdenv.mkDerivation rec {
     ++ optional pulseSupport libpulseaudio
     ++ optionals stdenv.isDarwin [ CoreServices AudioUnit AudioToolbox ];
 
-  NIX_LDFLAGS = []
+  NIX_LDFLAGS = toString ([]
     ++ optional alsaSupport "-lasound"
-    ++ optional pulseSupport "-lpulse";
+    ++ optional pulseSupport "-lpulse");
 
   meta = {
     description = "OpenAL alternative";
diff --git a/pkgs/development/libraries/opencv/3.x.nix b/pkgs/development/libraries/opencv/3.x.nix
index 97df84637ef..642facf166a 100644
--- a/pkgs/development/libraries/opencv/3.x.nix
+++ b/pkgs/development/libraries/opencv/3.x.nix
@@ -208,7 +208,7 @@ stdenv.mkDerivation {
 
   nativeBuildInputs = [ cmake pkgconfig unzip ];
 
-  NIX_CFLAGS_COMPILE = lib.optional enableEXR "-I${ilmbase.dev}/include/OpenEXR";
+  NIX_CFLAGS_COMPILE = lib.optionalString enableEXR "-I${ilmbase.dev}/include/OpenEXR";
 
   # Configure can't find the library without this.
   OpenBLAS_HOME = lib.optionalString enableOpenblas openblas;
diff --git a/pkgs/development/libraries/opencv/4.x.nix b/pkgs/development/libraries/opencv/4.x.nix
index 408368b89c4..9fffd3d9477 100644
--- a/pkgs/development/libraries/opencv/4.x.nix
+++ b/pkgs/development/libraries/opencv/4.x.nix
@@ -221,7 +221,7 @@ stdenv.mkDerivation {
 
   nativeBuildInputs = [ cmake pkgconfig unzip ];
 
-  NIX_CFLAGS_COMPILE = lib.optional enableEXR "-I${ilmbase.dev}/include/OpenEXR";
+  NIX_CFLAGS_COMPILE = lib.optionalString enableEXR "-I${ilmbase.dev}/include/OpenEXR";
 
   # Configure can't find the library without this.
   OpenBLAS_HOME = lib.optionalString enableOpenblas openblas;
diff --git a/pkgs/development/libraries/opencv/default.nix b/pkgs/development/libraries/opencv/default.nix
index db8a5e5a41b..ad27742d0b4 100644
--- a/pkgs/development/libraries/opencv/default.nix
+++ b/pkgs/development/libraries/opencv/default.nix
@@ -61,7 +61,7 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ cmake pkgconfig unzip ];
 
-  NIX_CFLAGS_COMPILE = lib.optional enableEXR "-I${ilmbase.dev}/include/OpenEXR";
+  NIX_CFLAGS_COMPILE = lib.optionalString enableEXR "-I${ilmbase.dev}/include/OpenEXR";
 
   cmakeFlags = [
     (opencvFlag "TIFF" enableTIFF)
diff --git a/pkgs/development/libraries/phonon/backends/gstreamer.nix b/pkgs/development/libraries/phonon/backends/gstreamer.nix
index 20723322c1d..d79078c2836 100644
--- a/pkgs/development/libraries/phonon/backends/gstreamer.nix
+++ b/pkgs/development/libraries/phonon/backends/gstreamer.nix
@@ -37,7 +37,7 @@ stdenv.mkDerivation rec {
             gst-plugins-bad
             gst-libav
           ]);
-    in [
+    in toString [
       # This flag should be picked up through pkgconfig, but it isn't.
       "-I${gst_all_1.gstreamer.dev}/lib/gstreamer-1.0/include"
 
diff --git a/pkgs/development/libraries/portaudio/default.nix b/pkgs/development/libraries/portaudio/default.nix
index 92b56467aee..68daece490f 100644
--- a/pkgs/development/libraries/portaudio/default.nix
+++ b/pkgs/development/libraries/portaudio/default.nix
@@ -13,7 +13,7 @@ stdenv.mkDerivation {
   buildInputs = [ libjack2 ]
     ++ stdenv.lib.optional (!stdenv.isDarwin) alsaLib;
 
-  configureFlags = [ "--disable-mac-universal --enable-cxx" ];
+  configureFlags = [ "--disable-mac-universal" "--enable-cxx" ];
 
   NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.cc.isClang "-Wno-error=nullability-inferred-on-nested-type -Wno-error=nullability-completeness-on-arrays";
 
diff --git a/pkgs/development/libraries/prometheus-cpp/default.nix b/pkgs/development/libraries/prometheus-cpp/default.nix
index b047322c35e..0403c7ad10c 100644
--- a/pkgs/development/libraries/prometheus-cpp/default.nix
+++ b/pkgs/development/libraries/prometheus-cpp/default.nix
@@ -30,7 +30,7 @@ stdenv.mkDerivation rec {
     "-DCIVETWEB_CXX_LIBRARY=${civetweb}/lib/libcivetweb${stdenv.targetPlatform.extensions.sharedLibrary}"
   ];
 
-  NIX_LDFLAGS = [ "-ldl" ];
+  NIX_LDFLAGS = "-ldl";
 
   meta = {
     description = "Prometheus Client Library for Modern C++";
diff --git a/pkgs/development/libraries/qoauth/default.nix b/pkgs/development/libraries/qoauth/default.nix
index 0d9ae21e87e..83e904e53eb 100644
--- a/pkgs/development/libraries/qoauth/default.nix
+++ b/pkgs/development/libraries/qoauth/default.nix
@@ -18,8 +18,8 @@ stdenv.mkDerivation {
   buildInputs = [ qt5.qtbase qca2-qt5 ];
   nativeBuildInputs = [ qt5.qmake ];
 
-  NIX_CFLAGS_COMPILE = [ "-I${qca2-qt5}/include/Qca-qt5/QtCrypto" ];
-  NIX_LDFLAGS = [ "-lqca-qt5" ];
+  NIX_CFLAGS_COMPILE = "-I${qca2-qt5}/include/Qca-qt5/QtCrypto";
+  NIX_LDFLAGS = "-lqca-qt5";
 
   meta = with stdenv.lib; {
     description = "Qt library for OAuth authentication";
diff --git a/pkgs/development/libraries/qt-4.x/4.8/default.nix b/pkgs/development/libraries/qt-4.x/4.8/default.nix
index 632b5fc1fd5..25953949eb7 100644
--- a/pkgs/development/libraries/qt-4.x/4.8/default.nix
+++ b/pkgs/development/libraries/qt-4.x/4.8/default.nix
@@ -206,13 +206,13 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
-  NIX_CFLAGS_COMPILE =
+  NIX_CFLAGS_COMPILE = toString (
     # with gcc7 the warnings blow the log over Hydra's limit
     [ "-Wno-expansion-to-defined" "-Wno-unused-local-typedefs" ]
     ++ lib.optional stdenv.isLinux "-std=gnu++98" # gnu++ in (Obj)C flags is no good on Darwin
     ++ lib.optionals (stdenv.isFreeBSD || stdenv.isDarwin)
       [ "-I${glib.dev}/include/glib-2.0" "-I${glib.out}/lib/glib-2.0/include" ]
-    ++ lib.optional stdenv.isDarwin "-I${libcxx}/include/c++/v1";
+    ++ lib.optional stdenv.isDarwin "-I${libcxx}/include/c++/v1");
 
   NIX_LDFLAGS = lib.optionalString (stdenv.isFreeBSD || stdenv.isDarwin) "-lglib-2.0";
 
diff --git a/pkgs/development/libraries/qt-5/mkDerivation.nix b/pkgs/development/libraries/qt-5/mkDerivation.nix
index 95357c096df..2c6333cb020 100644
--- a/pkgs/development/libraries/qt-5/mkDerivation.nix
+++ b/pkgs/development/libraries/qt-5/mkDerivation.nix
@@ -12,9 +12,9 @@ let
     qmakeFlags = [ ("CONFIG+=" + (if debug then "debug" else "release")) ]
               ++ (args.qmakeFlags or []);
 
-    NIX_CFLAGS_COMPILE =
+    NIX_CFLAGS_COMPILE = toString (
       optional (!debug) "-DQT_NO_DEBUG"
-      ++ lib.toList (args.NIX_CFLAGS_COMPILE or []);
+      ++ lib.toList (args.NIX_CFLAGS_COMPILE or []));
 
     cmakeFlags =
       (args.cmakeFlags or [])
diff --git a/pkgs/development/libraries/qt-5/modules/qtbase.nix b/pkgs/development/libraries/qt-5/modules/qtbase.nix
index c7cb6d509dc..bc23d0f9caf 100644
--- a/pkgs/development/libraries/qt-5/modules/qtbase.nix
+++ b/pkgs/development/libraries/qt-5/modules/qtbase.nix
@@ -170,11 +170,6 @@ stdenv.mkDerivation {
     export LD=$CXX
     ''}
 
-    configureFlags+="\
-        -plugindir $out/$qtPluginPrefix \
-        -qmldir $out/$qtQmlPrefix \
-        -docdir $out/$qtDocPrefix"
-
     NIX_CFLAGS_COMPILE+=" -DNIXPKGS_QT_PLUGIN_PREFIX=\"$qtPluginPrefix\""
   '';
 
@@ -200,20 +195,17 @@ stdenv.mkDerivation {
     done
   '';
 
-  NIX_CFLAGS_COMPILE =
-    [
-      "-Wno-error=sign-compare" # freetype-2.5.4 changed signedness of some struct fields
-      ''-DNIXPKGS_QTCOMPOSE="${libX11.out}/share/X11/locale"''
-      ''-D${if compareVersion "5.11.0" >= 0 then "LIBRESOLV_SO" else "NIXPKGS_LIBRESOLV"}="${stdenv.cc.libc.out}/lib/libresolv"''
-      ''-DNIXPKGS_LIBXCURSOR="${libXcursor.out}/lib/libXcursor"''
-    ]
-
-    ++ lib.optional libGLSupported ''-DNIXPKGS_MESA_GL="${libGL.out}/lib/libGL"''
+  NIX_CFLAGS_COMPILE = toString ([
+    "-Wno-error=sign-compare" # freetype-2.5.4 changed signedness of some struct fields
+    ''-DNIXPKGS_QTCOMPOSE="${libX11.out}/share/X11/locale"''
+    ''-D${if compareVersion "5.11.0" >= 0 then "LIBRESOLV_SO" else "NIXPKGS_LIBRESOLV"}="${stdenv.cc.libc.out}/lib/libresolv"''
+    ''-DNIXPKGS_LIBXCURSOR="${libXcursor.out}/lib/libXcursor"''
+  ] ++ lib.optional libGLSupported ''-DNIXPKGS_MESA_GL="${libGL.out}/lib/libGL"''
     ++ lib.optionals withGtk3 [
          ''-DNIXPKGS_QGTK3_XDG_DATA_DIRS="${gtk3}/share/gsettings-schemas/${gtk3.name}"''
          ''-DNIXPKGS_QGTK3_GIO_EXTRA_MODULES="${dconf.lib}/lib/gio/modules"''
        ]
-    ++ lib.optional decryptSslTraffic "-DQT_DECRYPT_SSL_TRAFFIC";
+    ++ lib.optional decryptSslTraffic "-DQT_DECRYPT_SSL_TRAFFIC");
 
   prefixKey = "-prefix ";
 
@@ -225,6 +217,10 @@ stdenv.mkDerivation {
   # TODO Remove obsolete and useless flags once the build will be totally mastered
   configureFlags =
     [
+      "-plugindir $(out)/$(qtPluginPrefix)"
+      "-qmldir $(out)/$(qtQmlPrefix)"
+      "-docdir $(out)/$(qtDocPrefix)"
+
       "-verbose"
       "-confirm-license"
       "-opensource"
diff --git a/pkgs/development/libraries/qtkeychain/default.nix b/pkgs/development/libraries/qtkeychain/default.nix
index 4951670f896..5b963255b65 100644
--- a/pkgs/development/libraries/qtkeychain/default.nix
+++ b/pkgs/development/libraries/qtkeychain/default.nix
@@ -24,12 +24,12 @@ stdenv.mkDerivation rec {
   cmakeFlags = [ "-DQT_TRANSLATIONS_DIR=share/qt/translations" ];
 
   nativeBuildInputs = [ cmake ]
-    ++ stdenv.lib.optional (!stdenv.isDarwin) [ pkgconfig ] # for finding libsecret
+    ++ stdenv.lib.optionals (!stdenv.isDarwin) [ pkgconfig ] # for finding libsecret
   ;
 
-  buildInputs = stdenv.lib.optional (!stdenv.isDarwin) [ libsecret ]
+  buildInputs = stdenv.lib.optionals (!stdenv.isDarwin) [ libsecret ]
     ++ (if withQt5 then [ qtbase qttools ] else [ qt4 ])
-    ++ stdenv.lib.optional stdenv.isDarwin (with darwin.apple_sdk.frameworks; [
+    ++ stdenv.lib.optionals stdenv.isDarwin (with darwin.apple_sdk.frameworks; [
       CoreFoundation Security
     ])
   ;
diff --git a/pkgs/development/libraries/science/benchmark/papi/default.nix b/pkgs/development/libraries/science/benchmark/papi/default.nix
index 35d0914e3f7..53ae70f5bf8 100644
--- a/pkgs/development/libraries/science/benchmark/papi/default.nix
+++ b/pkgs/development/libraries/science/benchmark/papi/default.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation {
     sha256 = "13mngf9kl0y2wfxqvkad0smdaag7k8fvw82b4312gx62nwhc1i6r";
   };
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error=format-truncation" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error=format-truncation";
 
   preConfigure = ''
     cd src
diff --git a/pkgs/development/libraries/science/math/osi/default.nix b/pkgs/development/libraries/science/math/osi/default.nix
index 1cc80e78a10..6dc7e746fd3 100644
--- a/pkgs/development/libraries/science/math/osi/default.nix
+++ b/pkgs/development/libraries/science/math/osi/default.nix
@@ -22,10 +22,10 @@ stdenv.mkDerivation rec {
     ++ lib.optionals withCplex [ "--with-cplex-incdir=${cplex}/cplex/include/ilcplex" "--with-cplex-lib=-lcplex${cplex.libSuffix}" ];
 
   NIX_LDFLAGS =
-    lib.optional withCplex "-L${cplex}/cplex/bin/${cplex.libArch}";
+    lib.optionalString withCplex "-L${cplex}/cplex/bin/${cplex.libArch}";
 
-  # Compile errors 
-  NIX_CFLAGS_COMPILE = [ "-Wno-cast-qual" ];
+  # Compile errors
+  NIX_CFLAGS_COMPILE = "-Wno-cast-qual";
   hardeningDisable = [ "format" ];
 
   enableParallelBuilding = true;
diff --git a/pkgs/development/libraries/smpeg/default.nix b/pkgs/development/libraries/smpeg/default.nix
index a7ffc146f41..4d74ee7ca06 100644
--- a/pkgs/development/libraries/smpeg/default.nix
+++ b/pkgs/development/libraries/smpeg/default.nix
@@ -40,7 +40,7 @@ stdenv.mkDerivation rec {
       --prefix PKG_CONFIG_PATH ":" "${SDL.dev}/lib/pkgconfig"
   '';
 
-  NIX_LDFLAGS = [ "-lX11" ];
+  NIX_LDFLAGS = "-lX11";
 
   meta = {
     homepage = http://icculus.org/smpeg/;
diff --git a/pkgs/development/libraries/spatialite-tools/default.nix b/pkgs/development/libraries/spatialite-tools/default.nix
index 2708e49eb2b..83eef355f2d 100644
--- a/pkgs/development/libraries/spatialite-tools/default.nix
+++ b/pkgs/development/libraries/spatialite-tools/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
-  NIX_LDFLAGS = [ "-lsqlite3" ];
+  NIX_LDFLAGS = "-lsqlite3";
 
   meta = {
     description = "A complete sqlite3-compatible CLI front-end for libspatialite";
diff --git a/pkgs/development/libraries/spdk/default.nix b/pkgs/development/libraries/spdk/default.nix
index e70980afac6..51583fdbbcd 100644
--- a/pkgs/development/libraries/spdk/default.nix
+++ b/pkgs/development/libraries/spdk/default.nix
@@ -23,7 +23,7 @@ stdenv.mkDerivation rec {
 
   configureFlags = [ "--with-dpdk=${dpdk}" ];
 
-  NIX_CFLAGS_COMPILE = [ "-mssse3" ]; # Necessary to compile.
+  NIX_CFLAGS_COMPILE = "-mssse3"; # Necessary to compile.
 
   enableParallelBuilding = true;
 
diff --git a/pkgs/development/libraries/sqlite/default.nix b/pkgs/development/libraries/sqlite/default.nix
index 5837361e01b..d904637fcd3 100644
--- a/pkgs/development/libraries/sqlite/default.nix
+++ b/pkgs/development/libraries/sqlite/default.nix
@@ -25,7 +25,7 @@ stdenv.mkDerivation rec {
 
   configureFlags = [ "--enable-threadsafe" ] ++ optional interactive "--enable-readline";
 
-  NIX_CFLAGS_COMPILE = [
+  NIX_CFLAGS_COMPILE = toString [
     "-DSQLITE_ENABLE_COLUMN_METADATA"
     "-DSQLITE_ENABLE_DBSTAT_VTAB"
     "-DSQLITE_ENABLE_JSON1"
diff --git a/pkgs/development/libraries/tinyxml/2.6.2.nix b/pkgs/development/libraries/tinyxml/2.6.2.nix
index cc7c996f7c3..0cc4038b64e 100644
--- a/pkgs/development/libraries/tinyxml/2.6.2.nix
+++ b/pkgs/development/libraries/tinyxml/2.6.2.nix
@@ -28,7 +28,7 @@ in stdenv.mkDerivation {
   hardeningDisable = [ "format" ];
 
   NIX_CFLAGS_COMPILE =
-    stdenv.lib.optional stdenv.isDarwin "-mmacosx-version-min=10.9";
+    stdenv.lib.optionalString stdenv.isDarwin "-mmacosx-version-min=10.9";
 
   buildInputs = [ unzip ];
   buildPhase = ''
diff --git a/pkgs/development/libraries/unixODBCDrivers/default.nix b/pkgs/development/libraries/unixODBCDrivers/default.nix
index 78f85afca91..6cfaef5ef99 100644
--- a/pkgs/development/libraries/unixODBCDrivers/default.nix
+++ b/pkgs/development/libraries/unixODBCDrivers/default.nix
@@ -100,16 +100,16 @@
   sqlite = stdenv.mkDerivation rec {
     pname = "sqlite-connector-odbc";
     version = "0.9993";
- 
+
     src = fetchurl {
       url = "http://www.ch-werner.de/sqliteodbc/sqliteodbc-${version}.tar.gz";
       sha256 = "0dgsj28sc7f7aprmdd0n5a1rmcx6pv7170c8dfjl0x1qsjxim6hs";
     };
- 
+
     buildInputs = [ unixODBC sqlite zlib libxml2 ];
- 
+
     configureFlags = [ "--with-odbc=${unixODBC}" ];
- 
+
     installTargets = [ "install-3" ];
 
     # move libraries to $out/lib where they're expected to be
@@ -117,7 +117,7 @@
       mkdir -p "$out/lib"
       mv "$out"/*.* "$out/lib"
     '';
- 
+
     passthru = {
       fancyName = "SQLite";
       driver = "lib/libsqlite3odbc.so";
diff --git a/pkgs/development/libraries/uri/default.nix b/pkgs/development/libraries/uri/default.nix
index 61246748ac7..5e5f4c9e8ca 100644
--- a/pkgs/development/libraries/uri/default.nix
+++ b/pkgs/development/libraries/uri/default.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
     sha256 = "148361pixrm94q6v04k13s1msa04bx9yc3djb0lxpa7dlw19vhcd";
   };
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error=parentheses" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error=parentheses";
 
   nativeBuildInputs = [ cmake doxygen ];
 
diff --git a/pkgs/development/libraries/usbredir/default.nix b/pkgs/development/libraries/usbredir/default.nix
index 2eee80a7696..8e43135196c 100644
--- a/pkgs/development/libraries/usbredir/default.nix
+++ b/pkgs/development/libraries/usbredir/default.nix
@@ -9,7 +9,7 @@ stdenv.mkDerivation rec {
     sha256 = "002yik1x7kn0427xahvnhjby2np14a6xqw7c3dx530n9h5d9rg47";
   };
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error";
 
   nativeBuildInputs = [ pkgconfig ];
   buildInputs = [ libusb ];
diff --git a/pkgs/development/libraries/v8/default.nix b/pkgs/development/libraries/v8/default.nix
index 4e9336172ad..a02e540173d 100644
--- a/pkgs/development/libraries/v8/default.nix
+++ b/pkgs/development/libraries/v8/default.nix
@@ -99,7 +99,7 @@ stdenv.mkDerivation rec {
 
   # with gcc8, -Wclass-memaccess became part of -Wall and causes logging limit
   # to be exceeded
-  NIX_CFLAGS_COMPILE = stdenv.lib.optional stdenv.cc.isGNU "-Wno-class-memaccess";
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.cc.isGNU "-Wno-class-memaccess";
 
   nativeBuildInputs = [ gn ninja pkgconfig python ]
     ++ stdenv.lib.optionals stdenv.isDarwin [ xcbuild darwin.DarwinTools ];
diff --git a/pkgs/development/libraries/wxwidgets/2.8/default.nix b/pkgs/development/libraries/wxwidgets/2.8/default.nix
index 38ee4376ac2..73dac47307a 100644
--- a/pkgs/development/libraries/wxwidgets/2.8/default.nix
+++ b/pkgs/development/libraries/wxwidgets/2.8/default.nix
@@ -44,7 +44,7 @@ stdenv.mkDerivation rec {
     + optionalString withMesa "${libGLU.out}/lib ${libGL.out}/lib ";
 
   # Work around a bug in configure.
-  NIX_CFLAGS_COMPILE = [ "-DHAVE_X11_XLIB_H=1" "-lX11" "-lcairo" "-Wno-narrowing" ];
+  NIX_CFLAGS_COMPILE = "-DHAVE_X11_XLIB_H=1 -lX11 -lcairo -Wno-narrowing";
 
   preConfigure = "
     substituteInPlace configure --replace 'SEARCH_INCLUDE=' 'DUMMY_SEARCH_INCLUDE='
diff --git a/pkgs/development/libraries/xmlsec/default.nix b/pkgs/development/libraries/xmlsec/default.nix
index 25c5bf45888..a8c751330b7 100644
--- a/pkgs/development/libraries/xmlsec/default.nix
+++ b/pkgs/development/libraries/xmlsec/default.nix
@@ -27,7 +27,7 @@ stdenv.mkDerivation {
   configureFlags = [ "--enable-soap" ];
 
   # otherwise libxmlsec1-gnutls.so won't find libgcrypt.so, after #909
-  NIX_LDFLAGS = [ "-lgcrypt" ];
+  NIX_LDFLAGS = "-lgcrypt";
 
   postInstall = ''
     moveToOutput "bin/xmlsec1-config" "$dev"
diff --git a/pkgs/development/libraries/zeroc-ice/default.nix b/pkgs/development/libraries/zeroc-ice/default.nix
index 945ba59cf3d..3a5b1690f2d 100644
--- a/pkgs/development/libraries/zeroc-ice/default.nix
+++ b/pkgs/development/libraries/zeroc-ice/default.nix
@@ -32,7 +32,7 @@ in stdenv.mkDerivation rec {
   buildInputs = [ zeroc_mcpp bzip2 expat openssl lmdb ]
     ++ lib.optionals stdenv.isDarwin [ darwin.cctools libiconv Security ];
 
-  NIX_CFLAGS_COMPILE = [ "-Wno-error=class-memaccess" "-Wno-error=deprecated-copy" ];
+  NIX_CFLAGS_COMPILE = "-Wno-error=class-memaccess -Wno-error=deprecated-copy";
 
   prePatch = lib.optional stdenv.isDarwin ''
     substituteInPlace Make.rules.Darwin \
diff --git a/pkgs/development/libraries/zookeeper_mt/default.nix b/pkgs/development/libraries/zookeeper_mt/default.nix
index ba53e8e5445..127ea4f7162 100644
--- a/pkgs/development/libraries/zookeeper_mt/default.nix
+++ b/pkgs/development/libraries/zookeeper_mt/default.nix
@@ -7,7 +7,7 @@ stdenv.mkDerivation rec {
 
   setSourceRoot = "export sourceRoot=${zookeeper.name}/src/c";
 
-  NIX_CFLAGS_COMPILE = stdenv.lib.optionals (!stdenv.isDarwin) [ "-Wno-error=format-overflow" "-Wno-error=stringop-truncation" ];
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString (!stdenv.isDarwin) "-Wno-error=format-overflow -Wno-error=stringop-truncation";
 
   buildInputs = [ zookeeper bash ];