error on build for qwt 6.1.6

stdave

Version: Qt 5.15.2
OS: Ubuntu 20.04.2
QWT 6.1.6

I have been attempting install of QWT with version 6.1.6 (get same problem with 6.1.3)

Issued qmake with no error on directory.
On make I get this in the display at beginning of build;

$ make
cd src/ && ( test -e Makefile || /usr/local/Qt/6.0.1/gcc_64/bin/qmake -o Makefile /home/david/Downloads/qwt-6.1.6/src/src.pro ) && make -f Makefile
make[1]: Entering directory '/home/david/Downloads/qwt-6.1.6/src'
compiling qwt_clipper.cpp
qwt_clipper.cpp: In member function ‘QVector<QwtInterval> QwtCircleClipper::clipCircle(const QPointF&, double) const’:
qwt_clipper.cpp:354:9: error: ‘qSort’ was not declared in this scope; did you mean ‘qSqrt’?
354 | qSort( angles );
| ^~~~~
| qSqrt
make[1]: *** [Makefile:4637: obj/qwt_clipper.o] Error 1
make[1]: Leaving directory '/home/david/Downloads/qwt-6.1.6/src'
make: *** [Makefile:50: sub-src-make_first-ordered] Error 2

I have searched forums for same error and have come up with nothing.
I followed the installation instructions like so;

/usr/local/Qt/6.0.1/gcc_64/bin/qmake qwt.pro

then

make

As I mentioned I get the identical error with both qwt versions 6.1.6 and 6.1.3.
Any pointers or suggestions would be welcome.

stdave

This particular error may be because qSort is apparently now obsolete. It has been replaced with std::sort
That said I am still running into errors - I'm now running into this error;

$ make
cd src/ && ( test -e Makefile || /usr/local/Qt/6.0.1/gcc_64/bin/qmake -o Makefile /home/david/Downloads/qwt-6.1.3/src/src.pro ) && make -f Makefile
make[1]: Entering directory '/home/david/Downloads/qwt-6.1.3/src'
compiling qwt_date.cpp
qwt_date.cpp: In static member function ‘static int QwtDate::utcOffset(const QDateTime&)’:
qwt_date.cpp:715:32: error: ‘const class QDateTime’ has no member named ‘utcOffset’
715 | seconds = dateTime.utcOffset();
| ^~~~~~~~~
make[1]: *** [Makefile:4922: obj/qwt_date.o] Error 1
make[1]: Leaving directory '/home/david/Downloads/qwt-6.1.3/src'
make: *** [Makefile:50: sub-src-make_first-ordered] Error 2
david@david-X510UAR:~/Downloads/qwt-6.1.3$

As before - any suggestions would be helpful - on my own here, trial-and-erroring myself to death.

SGaist

Hi,

From this feature request, you should use the 6.2 branch.

stdave

Ok - thanks for that. So I am now compiling and installing without errors. Next step is to get the qwt widgets to appear in Qt.
Here is where I stand;
Compiled and installed Qt into /usr/local/Qt version 5.15.2
Compiled qwt version (6.2.0) - using /usr/local/Qt/5.15.2/gcc_64/bin/qmake (checked using -v is 5.15.2)
Installed qwt into /usr/local/qwt-6.2.0-svn

This is a startup script I am using to get Qt up and running from the shell (so I can get some info)

QMAKEFEATURES=/usr/local/qwt-6.2.0-svn/features
QT_PLUGIN_PATH="/usr/local/qwt-6.2.0-svn/plugins:/usr/local/Qt/5.15.2/gcc_64/plugins"
QTDIR=/home/david/Qt
export QTDIR
export QT_PLUGIN_PATH
export QMAKEFEATURES
export QT_DEBUG_PLUGINS=1
/usr/local/Qt/Tools/QtCreator/bin/qtcreator

I put the plugin at;
/usr/local/Qt/5.15.2/gcc_64/plugins/designer/libqwt_designer_plugin.so

Here's something I found on old forums so I also did the following;

I inserted
/usr/local/qwt-6.2.0-svn/lib
into
/etc/ld.so.conf.d/qwt.conf
and updated with 'sudo ldconfig'

When I execute my shell file, I get quite a bit output - sending that through "grep qwt" I get;

QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/platformthemes" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/platforminputcontexts" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/xcbglintegrations" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/styles" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/sqldrivers" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/iconengines" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/imageformats" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/accessible" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/accessiblebridge" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qwt-6.2.0-svn/plugins/bearer" ...

I feel like I'm close - but still not there -

SGaist

Qt Creator is not designer. Start the Qt 5.15.2 designer and you'll likely see the Qwt widgets there.

stdave

OK - so, still closer, but a bug - I got this error;

Cannot load library /usr/local/Qt/5.15.2/gcc_64/plugins/designer/libqwt_designer_plugin.so: (/usr/local/Qt/5.15.2/gcc_64/plugins/designer/libqwt_designer_plugin.so: undefined symbol: _ZN17QwtDesignerPlugin18PolarPlotInterface12createWidgetEP7QWidget)

SGaist

What do you get if you run ldd on the plugin ?

stdave

$ ldd libqwt_designer_plugin.so

linux-vdso.so.1 (0x00007ffe464c5000)
libqwt.so.6.2 => /usr/local/qwt-6.2.0-svn/lib/libqwt.so.6.2 (0x00007f25ce791000)
libQt5Designer.so.5 => /usr/local/Qt/5.15.2/gcc_64/lib/libQt5Designer.so.5 (0x00007f25ce08f000)
libQt5Widgets.so.5 => /usr/local/Qt/5.15.2/gcc_64/lib/libQt5Widgets.so.5 (0x00007f25cd82d000)
libQt5Gui.so.5 => /usr/local/Qt/5.15.2/gcc_64/lib/libQt5Gui.so.5 (0x00007f25ccefc000)
libQt5Core.so.5 => /usr/local/Qt/5.15.2/gcc_64/lib/libQt5Core.so.5 (0x00007f25cc706000)
libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f25cc510000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f25cc4f3000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f25cc301000)
libQt5Svg.so.5 => /usr/local/Qt/5.15.2/gcc_64/lib/libQt5Svg.so.5 (0x00007f25cc0aa000)
libQt5OpenGL.so.5 => /usr/local/Qt/5.15.2/gcc_64/lib/libQt5OpenGL.so.5 (0x00007f25cbe53000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f25cbd04000)
libQt5Xml.so.5 => /usr/local/Qt/5.15.2/gcc_64/lib/libQt5Xml.so.5 (0x00007f25cbac6000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f25cbaa1000)
libGL.so.1 => /lib/x86_64-linux-gnu/libGL.so.1 (0x00007f25cba19000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f25cb9fd000)
libicui18n.so.56 => /usr/local/Qt/5.15.2/gcc_64/lib/libicui18n.so.56 (0x00007f25cb564000)
libicuuc.so.56 => /usr/local/Qt/5.15.2/gcc_64/lib/libicuuc.so.56 (0x00007f25cb1ac000)
libicudata.so.56 => /usr/local/Qt/5.15.2/gcc_64/lib/libicudata.so.56 (0x00007f25c97c7000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f25c97c1000)
libgthread-2.0.so.0 => /lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f25c97bc000)
libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f25c9693000)
/lib64/ld-linux-x86-64.so.2 (0x00007f25ce983000)
libGLdispatch.so.0 => /lib/x86_64-linux-gnu/libGLdispatch.so.0 (0x00007f25c95db000)
libGLX.so.0 => /lib/x86_64-linux-gnu/libGLX.so.0 (0x00007f25c95a5000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f25c9532000)
libX11.so.6 => /lib/x86_64-linux-gnu/libX11.so.6 (0x00007f25c93f5000)
libxcb.so.1 => /lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f25c93cb000)
libXau.so.6 => /lib/x86_64-linux-gnu/libXau.so.6 (0x00007f25c93c5000)
libXdmcp.so.6 => /lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f25c93bb000)
libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f25c93a1000)

SGaist

You may have to check the plugin code to see if there's something missing.

By the way, weren't you building with Qt 6 ?

stdave

@SGaist said in error on build for qwt 6.1.6:

You may have to check the plugin code to see if there's something missing.

By the way, weren't you building with Qt 6 ?

Originally I was - but things take a lot of twists and turns - I was getting errors building with the qmake from Qt6 - but that was with an older version of qwt - I tried several versions of qwt - all had the same compile problem, so I switched to a different version of Qt and have had more progress (so it seems).

Where exactly is the plugin code ? Are you talking about, for instance my shell script file - or maybe that I have plugin installed in /usr/local/Qt/5.15.2/gcc_64/plugins/designer - not sure if that should be there.

Oh, wait - you mean qwt. I can check that the configuration files I have been through and have not seen a reason to modify. Any suggestions as to what to look at?

SGaist

I would check the PolarPlot related stuff since it's from there that problem seems to be.

stdave

I recompiled qwt 6.2 with no errors. Tried a few different configuration. I removed the plugin file from within Qt.
Then I retried qwt-6.1.5 again and BINGO - the widgets are up and working. Thank you for your expert guidance on this.