anchor.diff:      mpeg2dec
       libmicrodns
       openjpeg
  +    libopenmpt
       libopus
       librsvg
       curl.dev
  
positive.code: , opencv4
  , openexr
  , openh264
  , pango
  , rtmpdump
  , sbc
  
negative.code:     # is needed, and then patching upstream to find it (though it probably
      # already works on Arch?).
      "-Dmusepack=disabled"
      "-Dopenni2=disabled" # not packaged in nixpkgs as of writing
      "-Dopensles=disabled" # not packaged in nixpkgs as of writing
      "-Dsctp=disabled" # required `usrsctp` library not packaged in nixpkgs as of writing
  