[Discuss-gnuradio] gnuradio-3.7.2, qwt6 and qtgui on gentoo

[Volker Schroer]

Hi

On an gentoo system with qwt-6.0.2 the qtgui builds nut fails to run.
The test reports
libgnuradio-qtgui-3.7.2git.so.0.0.0: undefined symbol: 
_ZNK7QwtPlot9drawItemsEP8QPainterRK6QRectFPK11QwtScaleMapq

This is due to mixture of qwt5 ( used for PyQt )and qwt libs.

FindQwt.cmake sets:

//Path to a file.
QWT_INCLUDE_DIRS:PATH=/usr/include/qwt6

//Path to a library.
QWT_LIBRARIES:FILEPATH=/usr/lib64/libqwt.so

But on gentoo

/usr/lib64/libqwt6.so -> libqwt6.so.6.0.2
/usr/lib64/libqwt6.so.6 -> libqwt6.so.6.0.2
/usr/lib64/libqwt6.so.6.0 -> libqwt6.so.6.0.2
/usr/lib64/libqwt6.so.6.0.2
/usr/lib64/libqwt.so -> libqwt.so.5.2.3
/usr/lib64/libqwt.so.5 -> libqwt.so.5.2.3
/usr/lib64/libqwt.so.5.2 -> libqwt.so.5.2.3
/usr/lib64/libqwt.so.5.2.3

So the header files are taken from qwt6 but the used library is qwt5 .

I suggest to change

find_library (QWT_LIBRARIES
  NAMES qwt qwt6 qwt-qt4

in FindQwt.cmake

to

find_library (QWT_LIBRARIES
  NAMES qwt6 qwt qwt-qt4

Then qtgui is build correctly and runs without problems.

But I don't know if there are side effects on other distros.

--Volker