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Project ERROR: Unknown module(s) in QT: webkitwidgets

Posted by: admin November 29, 2017 Leave a comment


I am porting code from qt4 to qt5. I added the following line to my .pro file, as suggested:

QT += webkitwidgets

However, when I run qmake, I get the this error:

Project ERROR: Unknown module(s) in QT: webkitwidgets

I am developing on Ubuntu 12.04 LTS and installed Qt as described.


You need to install the webkitwidgets library.

On Ubuntu, try this in a terminal:

sudo apt-get install libqt5webkit5-dev


If you need to install the webkit* Windows library for Qt 5.7 you should compile it manually because in new version webkit (WebView?) replaced by WebEngine.

Read about Qt 5.7 release (comments): http://blog.qt.io/blog/2016/06/16/qt-5-7-released/

Build sequence (static OR shared):

1) Download Qt 5.7.0 sources: http://download.qt.io/community_releases/5.7/5.7.0/

2) Download required tools: ActiveState Perl (binary), Python (binary), Ruby (binary), GnuWin Bison (binary), GPref (binary), Grep (binary), WinFlex, LibIconv, make (binary), sqlite (source!), ICU (source), windows msys (binary) (unix like shell with the tools), mingw-w64 (bin+dev) for build Qt with QtWebKit, see link on: https://trac.webkit.org/wiki/BuildingQtOnWindows

3) After download ICU source into C:\icu\icu. Open msys QT mingw console shell by open Start windows menu (msys should be downloaded and installed) and search or use fast search. In opened console start configure script and then compile and install:

$ cd C:\icu\icu\source

$ ./runConfigureICU

$ set PATH=%PATH%;C:\msys\1.0\bin\

$ make.exe

$ make.exe install

4) Build Qt with(!) ICU support (set “-icu” to configure) see compile script below. Change PATH to your environment.

Directory structure:

  • C:\Qt\5.7.0 – download binary version of Qt 5.7.0 here
  • C:\Qt\5.7.0n – directory for new (compiled) version of 5.7.0 (just make dir)
  • C:\Qt\Src – download source of Qt 5.7.0 here


set INCLUDE=C:\icu\icu\dist\include
set LIB=C:\icu\icu\dist\lib
set QTDIR=C:\Qt.7.0n
set PATH=%PATH%;C:\Qt\Qt5.7.0.7\mingw53_32\bin;C:\Qt\Qt5.7.0\Tools\QtCreator\bin;C:\Qt\Qt5.7.0\Tools\mingw530_32\bin;C:\Qt\Src\qtbase\bin;C:\Program Files (X86)\GnuWin32\bin;C:\winflex;C:\Ruby23-x64\bin;C:\Python27;C:\mingw-w64\i686-1\mingw32\bin;C:\icu\bin
set QMAKESPEC=win32-g++
set BUILD_DIR=C:\Qt\Qt5.7.0n
call C:\Qt\Src\qtbase\configure.bat -prefix %BUILD_DIR% -platform %QMAKESPEC% -confirm-license -debug-and-release -opensource -opengl desktop -no-compile-examples -icu -I C:/icu/icu/dist/include -L C:/icu/icu/dist/lib
jom.exe -j 4

Run command in exmaple in Windows Power Shell:

$ cd C:\Qt\Src\qtbase

$ ./compile.bat

After pass through compile use it to install files in the BUILD_DIR (install Qt files):

$ C:\mingw-w64\i686-1\mingw32\bin\mingw32-make.exe install

Qt should start to install

5) Download Qtwebkit sources to C:\Qt\Src\qtwebkit. Use compile script below to compile the qtwebkit using new Qt 5.7.0 build with files in C:\Qt\5.7.0n with ICU.


set INCLUDE=C:\sqlite
set LIBS=C:\sqlite
set SQLITE3SRCDIR=C:\sqlite
set QTDIR=C:\Qt\Qt5.7.0n
set PATH=%PATH%;C:\Qt\Qt5.7.0n\bin;C:\Qt\Src\qtbase\bin;C:\winflex;C:\Ruby23-x64\bin;C:\Python27;C:\mingw-w64\i686-1\mingw32\bin;C:\icu\bin;C:\Program Files (x86)\GnuWin32\bin
set QMAKESPEC=win32-g++
call perl.exe .\build-webkit --qt --release

Compile the qtwebkit:

$ cd C:\Qt\Src\qtwebkit\Tools\Scripts

$ ./compile.bat

$ cd C:\Qt\Src\qtwebkit\WebKitBuild\Release

$ C:\mingw-w64\i686-1\mingw32\bin\mingw32-make.exe install

It should be possible to compile your application with the qtwebkit after successfull compile and install.


Edit file C:\Qt\Src\qtbase\compile.bat and pass through build.

call C:\Qt\Src\qtbase\configure.bat -prefix %BUILD_DIR% -platform %QMAKESPEC% -confirm-license -debug-and-release -opensource -opengl desktop -static -no-compile-examples -icu
echo "QMAKE_FLAGS += -static -static-libgcc" >> .mkspecs/%QMAKESPEC%/qmake.conf


1) While build qtwebkit: "fatal error: unicode/uchar.h: No such file or directory"

Check that your Qt 5.7.0n build with ICU. IT also could notify you about “ICU required” at configure in qtwebkit.

2) flex: unknown flag '-'. For usage, try

You should use correct version of Flex that is “win_flex” in this case. You should rename files to use win_flex instead of just flex (and bison).

1) rename C:\Program Files (x86)\GnuWin32\bin\flex.exe to some unused name.

2) rename C:\Program Files (x86)\GnuWin32\bin\bison.exe to some unused name.

3) rename C:\winflex\win_bison.exe to bison.exe.

3) While build qtwebkit: "fatal error: sqlite3.h: No such file or directory"

Edit file C:\Qt\Src\qtwebkit\Tools\Scripts\compile.bat and check for correct path to sqlite:

set SQLITE3SRCDIR=C:\(path to some SQLITE .h/source files)

4) skipping incompatible ... when searching for ...

You should download right library arch (32bit or 64bit)

5) View.cpp ... undefined reference to WKPageCanGoBack

Could happens when pass through some test or MiniBrowser. You can search in files for the “UIProcess/API/qt” and “MiniBroswer” and remove it from
Makefile’s and some other files and then start build again.


Build Qt5: https://wiki.qt.io/Building_Qt_5_from_Git Qt WebKit build

like how to: https://trac.webkit.org/wiki/BuildingQtOnWindows ICU

build with GNU: https://wiki.qt.io/Compiling-ICU-with-MinGW


I got it to work by copying the webkit and webkitwidgets pri files from a previous installation, 5.5.



For windows, I just downloaded https://github.com/annulen/webkit/releases/tag/qtwebkit-tp5 and copied the folders to relevant Qt installation folder. Now I can use MinGW Qt5.8 with latest webkit. Thanks to Konstantin and all the contributors for this project!

Only one thing to note – I needed to use the release configuration in Qt.