I'm trying to build qt_gui_cpp_sip (melodic version 0.3.11) and cmake 3.13.x in a Debian stretch box using catkin version from here ros/catkin#998.

Although that patch solves some issues, still catkin or cmake or build system injects a -l-lpthread when it creates the Makefile for the SIP target. I have checked all the pkg files, and don't find where it comes from.

[ 94%] Compiling generated code for qt_gui_cpp_sip Python bindings...
/usr/bin/ld: cannot find -l-lpthread
collect2: error: ld returned 1 exit status
Makefile:37: recipe for target '"/srv/robotica/ros/src/qt_gui_core/qt_gui_cpp/build/devel/lib/python2.7/dist-packages/qt_gui_cpp/libqt_gui_cpp_sip".so' failed
make[4]: *** ["/srv/robotica/ros/src/qt_gui_core/qt_gui_cpp/build/devel/lib/python2.7/dist-packages/qt_gui_cpp/libqt_gui_cpp_sip".so] Error 1
src/qt_gui_cpp_sip/CMakeFiles/libqt_gui_cpp_sip.dir/build.make:60: recipe for target 'devel/lib/python2.7/dist-packages/qt_gui_cpp/libqt_gui_cpp_sip.so' failed

Any idea??