anchor.diff:      "--${boolEn (libgcrypt != null)}-gcrypt"
       "--${boolEn (gmp != null)}-gmp"
       "--${boolEn (gnutls != null)}-gnutls"
  -    (fflag "--${boolEn (aomedia != null)}-libaom" "4.0")
       "--${boolEn (stdenv.cc.libc != null)}-iconv"
       (deprfflag "--${boolEn (jack2_lib != null)}-jack" null "3.4")
       "--${boolEn (jni != null)}-jni"
       "--${boolEn (ladspa-sdk != null)}-ladspa"
  +    (fflag "--${boolEn (aomedia != null)}-libaom" "4.0")
  +    /**/(fflag "--disable-libaribb24" "4.1")
       "--${boolEn (libass != null)}-libass"
       "--${boolEn (libbluray != null)}-libbluray"
       "--${boolEn (libbs2b != null)}-libbs2b"
  
positive.code:     };
      "9.9" = {  # Git
        fetchzipversion = 6;
        version = "2018.08.21";
        rev = "24b24e14d64730ed90ae00744f091c74f30cff7a";
        sha256 = "99f022ee83dea7bee67d6e70e4cc8d905e0122056054e7c76e6eba17f044d80e";
      };
    };
    source = sources."${channel}";
  
negative.code:     "--${boolEn (x264 != null)}-libx264"
      "--${boolEn (x265 != null)}-libx265"
      "--${boolEn (xavs != null)}-libxavs"
      /**/(fflag "--disable-libxavs2" "4.1")
      #"--${boolEn (libxcb != null)}-libxcb"
      "--${boolEn libxcbshmExtlib}-libxcb-shm"
      "--${boolEn libxcbxfixesExtlib}-libxcb-xfixes"
  