I’m trying to install qwt 6.1.3 on Qt 6.7.0 and I have been following the installation guide at Qwt User’s Guide website, but whenever I try

mingw32-make

I receive the following error message:

C:Qwt-6.1.3qwt-6.1.3>mingw32-make
cd src && ( if not exist Makefile C:Qt6.7.0mingw_64binqmake.exe -o Makefile C:Qwt-6.1.3qwt-6.1.3srcsrc.pro ) && mingw32-make -f Makefile
mingw32-make[1]: Entering directory 'C:/Qwt-6.1.3/qwt-6.1.3/src'
mingw32-make -f Makefile.Release all
mingw32-make[2]: Entering directory 'C:/Qwt-6.1.3/qwt-6.1.3/src'
compiling qwt_abstract_scale_draw.cpp
In file included from qwt_abstract_scale_draw.h:15,
                 from qwt_abstract_scale_draw.cpp:10:
qwt_text.h:142:41: **error: 'null' is not a member of 'QString'**
  142 |     QwtText( const QString & = QString::null,
      |                                         ^~~~
mingw32-make[2]: *** [Makefile.Release:5651: release/qwt_abstract_scale_draw.o] Error 1
mingw32-make[2]: Leaving directory 'C:/Qwt-6.1.3/qwt-6.1.3/src'
mingw32-make[1]: *** [Makefile:49: release-all] Error 2
mingw32-make[1]: Leaving directory 'C:/Qwt-6.1.3/qwt-6.1.3/src'
mingw32-make: *** [Makefile:53: sub-src-make_first-ordered] Error 2

I don’t know what that means. I used the location of qtenv2.bat at mingw_64 to set the Qt command prompt (from windows command prompt) since “Qt version for Desktop” didn’t appear for me. I didn’t change anything in the qwt build and config.pri files and I’m not sure if I should have. I honestly don’t know where to go from here. Could anyone help?