anchor.diff:        msgpack
         ncurses
         neovimLuaEnv
  +      tree-sitter
         unibilium
       ] ++ optional stdenv.isDarwin libiconv
         ++ optionals doCheck [ glibcLocales procps ]
  
positive.code:       "-DGPERF_PRG=${gperf}/bin/gperf"
        "-DLUA_PRG=${neovimLuaEnv.interpreter}"
        "-DLIBLUV_LIBRARY=${luvpath}"
      ]
      ++ optional doCheck "-DBUSTED_PRG=${neovimLuaEnv}/bin/busted"
      ++ optional (!lua.pkgs.isLuaJIT) "-DPREFER_LUA=ON"
  
negative.code: , libuv, lua, ncurses, pkg-config
  , unibilium, xsel, gperf
  , libvterm-neovim
  , tree-sitter
  , glibcLocales ? null, procps ? null
  
  # now defaults to false because some tests can be flaky (clipboard etc)
  