Possible Errors during the build process for QtWebKit 5.6 with MSVC 2013

Do not panic when you encounter any of these errors.  Simply follow the steps below to fix the issue and continue the build process by running run nmake && nmake install again (or jom if you are using jom). The build process will continue from where it stopped.

1.  ICU is required Error

This error usually pops up when you run qmake -r CONFIG+=release without proper ICU configuration.

Encountered 2 configuration warning(s):

 ! Qt not configured to use system libjpeg, QImageDecoder will decode JPEG image
s
 ! Qt not configured to use system libpng, QImageDecoder will decode PNG images

The WebKit build was disabled for the following reasons:
    * ICU is required.
    * Missing gperf from PATH
    * Missing bison from PATH

    * Missing flex from PATH

Resolution

Put icu libraries in your environment variables.

SET INCLUDE=C:\icu\include;%INCLUDE%

SET LIB=C:\icu\lib64;%LIB%

For the others, ensure gnuwin32 utilities that come with qt5.6 source are in path.

SET PATH =C:\Qt5.6\gnuwin32\bin;%PATH%

   2.  Flex error 
      You may likely encounter this error if you use a different version of flex other than the one shipped with Qt 5.6 source.

Creating library ..\..\bin\jsc.lib and object ..\..\bin\jsc.exp
        cd Source\ThirdParty\ANGLE\ && ( if not exist Makefile.ANGLE C:\Qt\5.6\m
svc2013_64\bin\qmake.exe C:\qtwebkit\Source\ThirdParty\ANGLE\ANGLE.pro "CONFIG+=
release" -o Makefile.ANGLE ) && "C:\Program Files (x86)\Microsoft Visual Studio
12.0\VC\BIN\amd64\nmake.exe" -f Makefile.ANGLE

Microsoft (R) Program Maintenance Utility Version 12.00.21005.1
Copyright (C) Microsoft Corporation.  All rights reserved.

        ( if not exist Makefile.ANGLE.DerivedSources C:\Qt\5.6\msvc2013_64\bin\q
make.exe C:\qtwebkit\Source\ThirdParty\ANGLE\DerivedSources.pri "CONFIG+=release
" -o Makefile.ANGLE.DerivedSources ) && "C:\Program Files (x86)\Microsoft Visual
 Studio 12.0\VC\BIN\amd64\nmake.exe" -f Makefile.ANGLE.DerivedSources

Microsoft (R) Program Maintenance Utility Version 12.00.21005.1
Copyright (C) Microsoft Corporation.  All rights reserved.

        flex --noline --nounistd --outfile=generated\glslang_lex.cpp src\compile
r\glslang.l
C:\gnuwin32\bin\flex.EXE: unknown flag '-'.  For usage, try
        C:\gnuwin32\bin\flex.EXE --help
NMAKE : fatal error U1077: 'C:\gnuwin32\bin\flex.EXE' : return code '0x1'
Stop.
NMAKE : fatal error U1077: '(' : return code '0x2'
Stop.
NMAKE : fatal error U1077: 'cd' : return code '0x2'
Stop.

Resolution

Use the gnuwin32 utilities that come with qt5.6 source.