Bug#855866: GLFW3 has missing dependencies according to pkg-config

[Joaquín Montero Salinas]

Package: libglfw3-dev
Version: 3.0.4-1

When checking GLFW with `pkg-config --print-errors --exists`, I get
the following error message:
    $ pkg-config --print-errors --exists glfw3
    Package xrandr was not found in the pkg-config search path.
    Perhaps you should add the directory containing `xrandr.pc'
    to the PKG_CONFIG_PATH environment variable
    Package 'xrandr', required by 'glfw3', not found

libxrandr2 (version 2:1.4.2-1+b1) is installed as a dependency of libglfw3.

These are the contents of /usr/lib/x86_64-linux-gnu/pkgconfig/glfw3.pc:

    prefix=/usr
    exec_prefix=${prefix}
    includedir=${prefix}/include
    libdir=${exec_prefix}/lib/x86_64-linux-gnu

    Name: GLFW
    Description: A portable library for OpenGL, window and input
    Version: 3.0.4
    URL: http://www.glfw.org/
    Requires.private: xrandr x11 xi xxf86vm gl
    Libs: -L${libdir} -lglfw
    Libs.private:  -lrt -lm
    Cflags: -I${includedir}