bug#31659: powertabeditor fails to build since qt upgrade

[Ricardo Wurmus]

The powertabeditor package fails to build.  Errors include these:

--8<---------------cut here---------------start------------->8---
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:
 In constructor ‘BendDialog::BendDialog(QWidget*)’:
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:36:50:
 error: invalid use of incomplete type ‘class QButtonGroup’
     myDurationButtonGroup = new QButtonGroup(this);
                                                  ^
In file included from 
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:18:0:
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.h:24:7:
 note: forward declaration of ‘class QButtonGroup’
 class QButtonGroup;
       ^
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:37:26:
 error: invalid use of incomplete type ‘class QButtonGroup’
     myDurationButtonGroup->addButton(ui->defaultDurationButton);
                          ^
In file included from 
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:18:0:
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.h:24:7:
 note: forward declaration of ‘class QButtonGroup’
 class QButtonGroup;
       ^
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:38:26:
 error: invalid use of incomplete type ‘class QButtonGroup’
     myDurationButtonGroup->addButton(ui->customDurationButton);
                          ^
In file included from 
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:18:0:
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.h:24:7:
 note: forward declaration of ‘class QButtonGroup’
 class QButtonGroup;
       ^
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:
 In member function ‘void BendDialog::handleBendTypeChanged()’:
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:95:45:
 error: invalid use of incomplete type ‘class QButtonGroup’
     for (auto button : myDurationButtonGroup->buttons())
                                             ^
In file included from 
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:18:0:
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.h:24:7:
 note: forward declaration of ‘class QButtonGroup’
 class QButtonGroup;
       ^
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:103:53:
 error: invalid use of incomplete type ‘class QButtonGroup’
             for (auto button : myDurationButtonGroup->buttons())
                                                     ^
In file included from 
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:18:0:
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.h:24:7:
 note: forward declaration of ‘class QButtonGroup’
 class QButtonGroup;
       ^
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:115:53:
 error: invalid use of incomplete type ‘class QButtonGroup’
             for (auto button : myDurationButtonGroup->buttons())
                                                     ^
In file included from 
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:18:0:
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.h:24:7:
 note: forward declaration of ‘class QButtonGroup’
 class QButtonGroup;
       ^
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:122:53:
 error: invalid use of incomplete type ‘class QButtonGroup’
             for (auto button : myDurationButtonGroup->buttons())
                                                     ^
In file included from 
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.cpp:18:0:
/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/powertabeditor-2.0.0-alpha10/source/dialogs/benddialog.h:24:7:
 note: forward declaration of ‘class QButtonGroup’
 class QButtonGroup;
       ^
make[2]: *** [source/dialogs/CMakeFiles/ptedialogs.dir/build.make:330: 
source/dialogs/CMakeFiles/ptedialogs.dir/benddialog.cpp.o] Error 1
make[2]: Leaving directory 
'/tmp/guix-build-powertabeditor-2.0.0-alpha10.drv-0/build'
make[1]: *** [CMakeFiles/Makefile2:371: 
source/dialogs/CMakeFiles/ptedialogs.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
--8<---------------cut here---------------end--------------->8---


-- 
Ricardo