Requested 'gstreamer-video-1.0 >= 1.12' but version of GStreamer Video Library is 1.10.4

[flintforge]

I must be missing something about pkg_config and cargo.

cargo +nightly install hunter
On debian 9 the build fails at
Requested 'gstreamer-player-1.0 >= 1.12' but version of GStreamer Player is 1.10.4

getting and compiling gstreamer1.6 from the source release (not gitlab)

wget https://gstreamer.freedesktop.org/src/gstreamer/gstreamer-1.16.2.tar.xz 
tar -xJvf gstreamer-1.16.2.tar.xz 
./configure && make && make install

still
pkg-config --libs --cflags gstreamer-video-1.0 "gstreamer-video-1.0 >= 1.12"
returns Error 130 : Requested 'gstreamer-video-1.0 >= 1.12' but version of GStreamer Video Library is 1.10.4

So I added /usr/local/lib/pkgconfig/gstreamer-video-1.0.pc
containing

prefix=/usr/local/
exec_prefix=${prefix}
libdir=${prefix}/lib
includedir=${prefix}/include/gstreamer-1.0
datarootdir=${prefix}/share
datadir=${datarootdir}
girdir=${datadir}/gir-1.0
typelibdir=${libdir}/girepository-1.0

Name: GStreamer Video Library
Description: Video base classes and helper functions
Requires: gstreamer-1.0 gstreamer-base-1.0
Version: 1.16.2
Libs: -L${libdir} -lgstvideo-1.0
Cflags: -I${includedir}

... and which looks fine to me

now the previous pkg-config command runs fine,
but still, the cargo install returns the same error,
even with a PKG_CONFIG_PATH=/usr/local/lib/pkgconfig prepended at the command line