default.nix

  # If this source is local, strip a bunch of things from the source before
  # building to make the hash change a little less often on local machines.
  # This doesn't filter non-local sources.
  maybeFilterSource = src:
    if !isList src &&
       !isFunction src &&
       !isDerivation src &&
       !isStorePath src
      then defaultSourceFilter src
      else src;

  # Filter source with some sensible defaults
	defaultSourceFilter =
    builtins.filterSource (path: type:
      type != "unknown" &&
      baseNameOf path != ".gitignore" &&
      baseNameOf path != "result" &&
      !(hasSuffix "~" path) &&
      (baseNameOf path == ".git"        -> type != "directory") &&
      (baseNameOf path == "dist"        -> type != "directory") &&
      (baseNameOf path == "make"        -> type != "directory") &&
      (baseNameOf path == ".stack-work" -> type != "directory")
    );