Bug#944668: mupen64plus-core: FTBFS against opencv 4.1: "No OpenCV development libraries found!" during debian/rules clean

[Andreas Beckmann]

Source: mupen64plus-core
Version: 2.5.9-1
Severity: serious
Tags: ftbfs
Justification: fails to build from source (but built successfully in the past)
User: debian-qa at lists.debian.org
Usertags: piuparts
Control: affects -1 + libmupen64plus2

mupen64plus-core/experimental FTBFS against opencv 4.1 which is now in
sid:

 fakeroot debian/rules clean
dh clean --sourcedirectory="projects/unix"
   debian/rules override_dh_auto_clean
make[1]: Entering directory '/build/mupen64plus-core-2.5.9'
dh_auto_clean -- V=1 UNAME='linux' HOST_CPU='x86_64' APIDIR=/usr/include/mupen64plus/ DEBUG=1 DEBUGGER=1 PREFIX=/usr/ LIBDIR="/usr/lib/x86_64-linux-gnu" PIC=1 OPTFLAGS="-DNDEBUG" SHAREDIR="/usr/share/games/mupen64plus/" SDL_CONFIG=sdl2-config OPENCV=1
        cd projects/unix && make -j16 distclean V=1 UNAME=linux HOST_CPU=x86_64 APIDIR=/usr/include/mupen64plus/ DEBUG=1 DEBUGGER=1 PREFIX=/usr/ LIBDIR=/usr/lib/x86_64-linux-gnu PIC=1 OPTFLAGS=-DNDEBUG SHAREDIR=/usr/share/games/mupen64plus/ SDL_CONFIG=sdl2-config OPENCV=1
make[2]: Entering directory '/build/mupen64plus-core-2.5.9/projects/unix'
Makefile:305: *** No OpenCV development libraries found!.  Stop.
make[2]: Leaving directory '/build/mupen64plus-core-2.5.9/projects/unix'
dh_auto_clean: cd projects/unix && make -j16 distclean V=1 UNAME=linux HOST_CPU=x86_64 APIDIR=/usr/include/mupen64plus/ DEBUG=1 DEBUGGER=1 PREFIX=/usr/ LIBDIR=/usr/lib/x86_64-linux-gnu PIC=1 OPTFLAGS=-DNDEBUG SHAREDIR=/usr/share/games/mupen64plus/ SDL_CONFIG=sdl2-config OPENCV=1 returned exit code 2
make[1]: *** [debian/rules:30: override_dh_auto_clean] Error 255
make[1]: Leaving directory '/build/mupen64plus-core-2.5.9'
make: *** [debian/rules:24: clean] Error 2
dpkg-buildpackage: error: fakeroot debian/rules clean subprocess returned exit status 2


Andreas