Thanks Cinaed , I tried your method and it turns out that I have 'libqwt6abi1/stable,now 6.1.2-6 armhf [installed]' and similarly I have QT version of 'Using Qt version 5.7.1 in /usr/lib/arm-linux-gnueabihf ' installed. The error in 'make' of gr-radar is still occurring. I don't know the reason. I have shared the error details before but for convenience I am sharing again.
In file included from /home/pi/gr-radar/build/lib/moc_scatter_plot.cxx:9:0:
/home/pi/gr-radar/build/lib/../../lib/scatter_plot.h:24:22: fatal error: qwt_plot.h: No such file or directory
#include <qwt_plot.h>
^
compilation terminated.
lib/CMakeFiles/gnuradio-radar.dir/build.make:77: recipe for target 'lib/CMakeFiles/gnuradio-radar.dir/moc_scatter_plot.cxx.o' failed
make[2]: *** [lib/CMakeFiles/gnuradio-radar.dir/moc_scatter_plot.cxx.o] Error 1
CMakeFiles/Makefile2:137: recipe for target 'lib/CMakeFiles/gnuradio-radar.dir/all' failed
make[1]: *** [lib/CMakeFiles/gnuradio-radar.dir/all] Error 2
Makefile:138: recipe for target 'all' failed
make: *** [all] Error 2
Regards
Talha Farooq Hashmi