{
  stdenv, lib, copyPathsToStore,
  src, version,

  coreutils, bison, flex, gdb, gperf, lndir, patchelf, perl, pkgconfig, python2,
  ruby,
  # darwin support
  darwin, libiconv, libcxx,

  dbus, fontconfig, freetype, glib, gtk3, harfbuzz, icu, libX11, libXcomposite,
  libXcursor, libXext, libXi, libXrender, libinput, libjpeg, libpng, libtiff,
  libxcb, libxkbcommon, libxml2, libxslt, openssl, pcre16, sqlite, udev,
  xcbutil, xcbutilimage, xcbutilkeysyms, xcbutilrenderutil, xcbutilwm, xlibs,
  zlib,

  # optional dependencies
  cups ? null, mysql ? null, postgresql ? null,

  # options
  mesaSupported ? (!stdenv.isDarwin),
  mesa,
  buildExamples ? false,
  buildTests ? false,
  developerBuild ? false,
  decryptSslTraffic ? false
}:

let
  system-x86_64 = lib.elem stdenv.system lib.platforms.x86_64;
in

stdenv.mkDerivation {

  name = "qtbase-${version}";
  inherit src version;

  outputs = [ "out" "dev" ];

  patches =
    copyPathsToStore (lib.readPathsFromFile ./. ./series)
    ++ [(if stdenv.isDarwin then ./cmake-paths-darwin.patch else ./cmake-paths.patch)]
    ++ lib.optional decryptSslTraffic ./decrypt-ssl-traffic.patch
    ++ lib.optionals mesaSupported [ ./mkspecs-libgl.patch ];

  postPatch =
    ''
      substituteInPlace configure --replace /bin/pwd pwd
      substituteInPlace src/corelib/global/global.pri --replace /bin/ls ${coreutils}/bin/ls
      sed -e 's@/\(usr\|opt\)/@/var/empty/@g' -i config.tests/*/*.test -i mkspecs/*/*.conf

      sed -i 's/PATHS.*NO_DEFAULT_PATH//' "src/corelib/Qt5Config.cmake.in"
      sed -i 's/PATHS.*NO_DEFAULT_PATH//' "src/corelib/Qt5CoreMacros.cmake"
      sed -i 's/NO_DEFAULT_PATH//' "src/gui/Qt5GuiConfigExtras.cmake.in"
      sed -i 's/PATHS.*NO_DEFAULT_PATH//' "mkspecs/features/data/cmake/Qt5BasicConfig.cmake.in"
    ''
    + lib.optionalString mesaSupported ''
      substituteInPlace mkspecs/common/linux.conf \
        --replace "@mesa_lib@" "${mesa.out}" \
        --replace "@mesa_inc@" "${mesa.dev or mesa}"
    ''+ lib.optionalString stdenv.isDarwin ''
      sed -i \
          -e 's|! /usr/bin/xcode-select --print-path >/dev/null 2>&1;|false;|' \
          -e 's|! /usr/bin/xcrun -find xcodebuild >/dev/null 2>&1;|false;|' \
          -e 's|sysroot=$(/usr/bin/xcodebuild -sdk $sdk -version Path 2>/dev/null)|sysroot=/nonsense|' \
          -e 's|QMAKE_CONF_COMPILER=`getXQMakeConf QMAKE_CXX`|QMAKE_CXX="clang++"\nQMAKE_CONF_COMPILER="clang++"|' \
          -e 's|XCRUN=`/usr/bin/xcrun -sdk macosx clang -v 2>&1`|XCRUN="clang -v 2>&1"|' \
          -e 's#sdk_val=$(/usr/bin/xcrun -sdk $sdk -find $(echo $val | cut -d \x27 \x27 -f 1))##' \
          -e 's#val=$(echo $sdk_val $(echo $val | cut -s -d \x27 \x27 -f 2-))##' \
          ./configure
      sed -i '3,$d' ./mkspecs/features/mac/default_pre.prf
      sed -i '26,$d' ./mkspecs/features/mac/default_post.prf
      sed -i '1,$d' ./mkspecs/features/mac/sdk.prf
      sed -i 's/QMAKE_LFLAGS_RPATH      = -Wl,-rpath,/QMAKE_LFLAGS_RPATH      =/' ./mkspecs/common/mac.conf
     '';
     # Note on the above: \x27 is a way if including a single-quote
     # character in the sed string arguments.

  setOutputFlags = false;
  preConfigure = ''
    export LD_LIBRARY_PATH="$PWD/lib:$PWD/plugins/platforms:$LD_LIBRARY_PATH"
    export MAKEFLAGS=-j$NIX_BUILD_CORES

    configureFlags+="\
        -plugindir $out/lib/qt5/plugins \
        -importdir $out/lib/qt5/imports \
        -qmldir $out/lib/qt5/qml \
        -docdir $out/share/doc/qt5"

    NIX_CFLAGS_COMPILE+=" -DNIXPKGS_QPA_PLATFORM_PLUGIN_PATH=\"''${!outputLib}/lib/qt5/plugins\""
  '';

  prefixKey = "-prefix ";

  # -no-eglfs, -no-directfb, -no-linuxfb and -no-kms because of the current minimalist mesa
  # TODO Remove obsolete and useless flags once the build will be totally mastered
  configureFlags = ''
    -verbose
    -confirm-license
    -opensource

    -release
    -shared
    ${lib.optionalString developerBuild "-developer-build"}
    -accessibility
    -optimized-qmake
    -strip
    -no-reduce-relocations
    -system-proxies
    -pkg-config

    -gui
    -widgets
    -opengl desktop
    -qml-debug
    -icu
    -pch

    ${lib.optionalString (!system-x86_64) "-no-sse2"}
    -no-sse3
    -no-ssse3
    -no-sse4.1
    -no-sse4.2
    -no-avx
    -no-avx2
    -no-mips_dsp
    -no-mips_dspr2

    -system-zlib
    -system-libjpeg
    -system-harfbuzz
    -system-pcre
    -openssl-linked

    -system-sqlite
    -${if mysql != null then "plugin" else "no"}-sql-mysql
    -${if postgresql != null then "plugin" else "no"}-sql-psql

    -make libs
    -make tools
    -${lib.optionalString (buildExamples == false) "no"}make examples
    -${lib.optionalString (buildTests == false) "no"}make tests
    -v
  '' + lib.optionalString (!stdenv.isDarwin) ''
    -rpath
    -glib
    -xcb
    -qpa xcb

    -${lib.optionalString (cups == null) "no-"}cups

    -no-eglfs
    -no-directfb
    -no-linuxfb
    -no-kms

    -libinput
    -gtk
    -system-libpng
    -system-xcb
    -system-xkbcommon
    -dbus-linked
  '' + lib.optionalString stdenv.isDarwin ''
    -platform macx-clang
    -no-use-gold-linker
    -no-fontconfig
    -qt-freetype
    -qt-libpng
  '';

  # PostgreSQL autodetection fails sporadically because Qt omits the "-lpq" flag
  # if dependency paths contain the string "pq", which can occur in the hash.
  # To prevent these failures, we need to override PostgreSQL detection.
  PSQL_LIBS = lib.optionalString (postgresql != null) "-L${postgresql.lib}/lib -lpq";

  propagatedBuildInputs = [
    libxml2 libxslt openssl pcre16 sqlite zlib

    # Text rendering
    harfbuzz icu

    # Image formats
    libjpeg libpng libtiff
  ]
  ++ lib.optional mesaSupported mesa
  ++ lib.optionals (!stdenv.isDarwin) [
    dbus glib udev

    # Text rendering
    fontconfig freetype

    # X11 libs
    libX11 libXcomposite libXext libXi libXrender libxcb libxkbcommon xcbutil
    xcbutilimage xcbutilkeysyms xcbutilrenderutil xcbutilwm
  ] ++ lib.optionals stdenv.isDarwin (with darwin.apple_sdk.frameworks; [
    AGL AppKit ApplicationServices Carbon Cocoa
    CoreAudio CoreBluetooth CoreLocation CoreServices
    DiskArbitration Foundation OpenGL
    darwin.cf-private darwin.libobjc libiconv
  ]);

  buildInputs = [ ]
    ++ lib.optionals (!stdenv.isDarwin) [ gtk3 libinput ]
    ++ lib.optional developerBuild gdb
    ++ lib.optional (cups != null) cups
    ++ lib.optional (mysql != null) mysql.lib
    ++ lib.optional (postgresql != null) postgresql;

  nativeBuildInputs = [ bison flex gperf lndir perl pkgconfig python2 ] ++ lib.optional (!stdenv.isDarwin) patchelf;

  # freetype-2.5.4 changed signedness of some struct fields
  NIX_CFLAGS_COMPILE =
    [
      "-Wno-error=sign-compare"
      ''-DNIXPKGS_QTCOMPOSE="${libX11.out}/share/X11/locale"''
      ''-DNIXPKGS_LIBRESOLV="${stdenv.cc.libc.out}/lib/libresolv"''
      ''-DNIXPKGS_LIBXCURSOR="${libXcursor.out}/lib/libXcursor"''
      ''-DNIXPKGS_LIBSSL="${openssl.out}/lib/libssl"''
      ''-DNIXPKGS_LIBCRYPTO="${openssl.out}/lib/libcrypto"''
      (if stdenv.isLinux
        then ''-DNIXPKGS_LIBDBUS="${dbus.lib}/lib/libdbus-1"''
        else ''-DNIXPKGS_LIBDBUS=""'')
    ]
    ++ lib.optional mesaSupported
       ''-DNIXPKGS_MESA_GL="${mesa.out}/lib/libGL"''
    ++ lib.optionals stdenv.isDarwin
    [
      "-D__MAC_OS_X_VERSION_MAX_ALLOWED=1090"
      "-D__AVAILABILITY_INTERNAL__MAC_10_10=__attribute__((availability(macosx,introduced=10.10)))"
      # Note that nixpkgs's objc4 is from macOS 10.11 while the SDK is
      # 10.9 which necessitates the above macro definition that mentions
      # 10.10
    ];

  postInstall = ''
    find "$out" -name "*.cmake" | while read file; do
        substituteInPlace "$file" \
            --subst-var-by NIX_OUT "$out" \
            --subst-var-by NIX_DEV "$dev"
    done
  '';

  preFixup = ''
    # We cannot simply set these paths in configureFlags because libQtCore retains
    # references to the paths it was built with.
    moveToOutput "bin" "$dev"
    moveToOutput "include" "$dev"
    moveToOutput "mkspecs" "$dev"

    # The destination directory must exist or moveToOutput will do nothing
    mkdir -p "$dev/share"
    moveToOutput "share/doc" "$dev"
  '';

  postFixup =
    ''
      # Don't retain build-time dependencies like gdb.
      sed '/QMAKE_DEFAULT_.*DIRS/ d' -i $dev/mkspecs/qconfig.pri

      # Move libtool archives and qmake projects
      if [ "z''${!outputLib}" != "z''${!outputDev}" ]; then
          pushd "''${!outputLib}"
          find lib -name '*.a' -o -name '*.la'${if stdenv.isDarwin then "" else "-o -name '*.prl'"} | \
              while read -r file; do
                  mkdir -p "''${!outputDev}/$(dirname "$file")"
                  mv "''${!outputLib}/$file" "''${!outputDev}/$file"
              done
          popd
      fi
    ''
    # fixup .pc file (where to find 'moc' etc.)
    + lib.optionalString (!stdenv.isDarwin) ''
      sed -i "$dev/lib/pkgconfig/Qt5Core.pc" \
          -e "/^host_bins=/ c host_bins=$dev/bin"
    ''
    # Don' move .prl files on darwin because they end up in
    # "dev/lib/Foo.framework/Foo.prl" which interferes with subsequent
    # use of lndir in the qtbase setup-hook. On Linux, the .prl files
    # are in lib, and so do not cause a subsequent recreation of deep
    # framework directory trees.
    + lib.optionalString stdenv.isDarwin ''
      fixDarwinDylibNames_rpath() {
        local flags=()

        for fn in "$@"; do
          flags+=(-change "@rpath/$fn.framework/Versions/5/$fn" "$out/lib/$fn.framework/Versions/5/$fn")
        done

        for fn in "$@"; do
          echo "$fn: fixing dylib"
          install_name_tool -id "$out/lib/$fn.framework/Versions/5/$fn" "''${flags[@]}" "$out/lib/$fn.framework/Versions/5/$fn"
        done
      }
      fixDarwinDylibNames_rpath "QtConcurrent" "QtPrintSupport" "QtCore" "QtSql" "QtDBus" "QtTest" "QtGui" "QtWidgets" "QtNetwork" "QtXml" "QtOpenGL"
    '';

  inherit lndir;
  setupHook = if stdenv.isDarwin
              then ../../qtbase-setup-hook-darwin.sh
              else ../../qtbase-setup-hook.sh;

  enableParallelBuilding = true;

  meta = with lib; {
    homepage = http://www.qt.io;
    description = "A cross-platform application framework for C++";
    license = with licenses; [ fdl13 gpl2 lgpl21 lgpl3 ];
    maintainers = with maintainers; [ qknight ttuegel periklis ];
    platforms = platforms.unix;
  };

}