Qt 6.0 dev error build from sources linux error: qxcbintegration.h:63:1: error: expected class-name before ‘{’ token

commit 35b431cb9e46bcab29240c555e652f4f9cab0895 (HEAD -> dev, origin/dev, origin/HEAD)
Author: Tony Sarajärvi <tony.sarajarvi@qt.io>
Date: Mon May 25 09:12:05 2020 +0000
Remove Windows 7 builds from Qt6
 
 Task-number: QTQAINFRA-3750
 Change-Id: Iea7ccca4695ce3f72547044ee2371c761f026eb4
 Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

g++ -c -pipe -O2 -fPIC -std=c++1z -fvisibility=hidden -fvisibility-inlines-hidden -fno-exceptions -Wall -Wextra -Wvla -Wdate-time -Wshift-overflow=2 -Wduplicated-cond -Wno-stringop-overflow -ffunction-sections -fdata-sections -D_REENTRANT -DQT_NO_JAVA_STYLE_ITERATORS -DQT_NO_FOREACH -DQT_BUILD_XCB_PLUGIN -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_BUILD_XCB_QPA_LIB_LIB -DQT_BUILDING_QT -DQT_NO_CAST_TO_ASCII -DQT_ASCII_CAST_WARNINGS -DQT_MOC_COMPAT -DQT_USE_QSTRINGBUILDER -DQT_DEPRECATED_WARNINGS -DQT_DISABLE_DEPRECATED_BEFORE=0x050000 -DQT_DEPRECATED_WARNINGS_SINCE=0x060000 -DQT_NO_EXCEPTIONS -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DQT_XKBCOMMON_SUPPORT_LIB -DQT_OPENGL_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I. -Igl_integrations -I../../../../include -I../../../../include/QtXkbCommonSupport -I../../../../include/QtXkbCommonSupport/6.0.0 -I../../../../include/QtXkbCommonSupport/6.0.0/QtXkbCommonSupport -I../../../../include/QtOpenGL/6.0.0 -I../../../../include/QtOpenGL/6.0.0/QtOpenGL -I../../../../include/QtGui/6.0.0 -I../../../../include/QtGui/6.0.0/QtGui -I../../../../include/QtOpenGL -I../../../../include/QtGui -I../../../../include/QtCore/6.0.0 -I../../../../include/QtCore/6.0.0/QtCore -I../../../../include/QtCore -I.moc -I/usr/include/libdrm -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/xcb -I/usr/include/xcb -I../../../../mkspecs/linux-g++ -o .obj/qxcbintegration.o qxcbintegration.cpp
In file included from qxcbintegration.cpp:40:
qxcbintegration.h:63:1: error: expected class-name before ‘{’ token
 {
 ^
qxcbintegration.h:74:21: error: expected ‘;’ at end of member declaration
     QOpenGLContext *createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const override;
                     ^~~~~~~~~~~~~~~~~~~
                                        ;
qxcbintegration.h:74:41: error: ‘QOpenGLContext* QXcbIntegration::createOpenGLContext’ conflicts with a previous declaration
     QOpenGLContext *createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const override;
                                         ^~~~~~~~~~
qxcbintegration.h:73:21: note: previous declaration ‘QOpenGLContext* QXcbIntegration::createOpenGLContext(GLXContext, void*, QOpenGLContext*) const’
     QOpenGLContext *createOpenGLContext(GLXContext context, void *visualInfo, QOpenGLContext *shareContext) const override;
                     ^~~~~~~~~~~~~~~~~~~
qxcbintegration.h:74:51: error: expected ‘)’ before ‘context’
     QOpenGLContext *createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const override;
                                        ~          ^~~~~~~~
                                                   )
In file included from qxcbconnection.cpp:53:
qxcbintegration.h:63:1: error: expected class-name before ‘{’ token
 {
 ^
qxcbintegration.h:74:21: error: expected ‘;’ at end of member declaration
     QOpenGLContext *createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const override;
                     ^~~~~~~~~~~~~~~~~~~
                                        ;
qxcbintegration.h:74:41: error: ‘QOpenGLContext* QXcbIntegration::createOpenGLContext’ conflicts with a previous declaration
     QOpenGLContext *createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const override;
                                         ^~~~~~~~~~
qxcbintegration.h:73:21: note: previous declaration ‘QOpenGLContext* QXcbIntegration::createOpenGLContext(GLXContext, void*, QOpenGLContext*) const’
     QOpenGLContext *createOpenGLContext(GLXContext context, void *visualInfo, QOpenGLContext *shareContext) const override;
                     ^~~~~~~~~~~~~~~~~~~
qxcbintegration.h:74:51: error: expected ‘)’ before ‘context’
     QOpenGLContext *createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const override;
                                        ~          ^~~~~~~~
                                                   )
qxcbintegration.cpp:288:54: error: ‘QOpenGLContext* QXcbIntegration::createOpenGLContext’ is not a static data member of ‘class QXcbIntegration’
 QOpenGLContext *QXcbIntegration::createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const
                                                      ^~~~~~~~~~
qxcbintegration.cpp:288:54: error: ‘EGLContext’ was not declared in this scope
qxcbintegration.cpp:288:54: note: suggested alternative: ‘GContext’
 QOpenGLContext *QXcbIntegration::createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const
                                                      ^~~~~~~~~~
                                                      GContext
qxcbintegration.cpp:288:74: error: ‘EGLDisplay’ was not declared in this scope
 QOpenGLContext *QXcbIntegration::createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const
                                                                          ^~~~~~~~~~
qxcbintegration.cpp:288:74: note: suggested alternative: ‘Display’
 QOpenGLContext *QXcbIntegration::createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const
                                                                          ^~~~~~~~~~
                                                                          Display
qxcbintegration.cpp:288:109: error: expected primary-expression before ‘*’ token
 QOpenGLContext *QXcbIntegration::createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const
                                                                                                             ^
qxcbintegration.cpp:288:110: error: ‘shareContext’ was not declared in this scope
 QOpenGLContext *QXcbIntegration::createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const
                                                                                                              ^~~~~~~~~~~~
qxcbintegration.cpp:288:110: note: suggested alternative: ‘GMainContext’
 QOpenGLContext *QXcbIntegration::createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const
                                                                                                              ^~~~~~~~~~~~
                                                                                                              GMainContext
qxcbintegration.cpp:288:122: error: expression list treated as compound expression in initializer [-fpermissive]
 QOpenGLContext *QXcbIntegration::createOpenGLContext(EGLContext context, EGLDisplay display, QOpenGLContext *shareContext) const

./configure  -openssl-linked -static -skip qt3d -no-warnings-are-errors  -release -recheck-all -prefix /Static600 -opensource -confirm-license -nomake examples -nomake tests -c++std c++17 -I /usr/include/xcb/ -L /usr/lib/x86_64-linux-gnu/ -xcb-xlib -xcb -feature-thread -feature-xkbcommon -qt-libpng -qt-libjpeg -qt-zlib  -I /usr/include/xcb/ -L /usr/lib/x86_64-linux-gnu/