message: Propagate file-related error messages to the screen.
diff: @@ -223,9 +223,13 @@ StatusOr<HloSnapshot> ParseInputFile(const string& filename,
  const Options& opts) {
  tensorflow::Env* env = tensorflow::Env::Default();
  HloSnapshot snapshot;
  - if (tensorflow::ReadBinaryProto(env, filename, &snapshot).ok()) {
  + auto s = tensorflow::ReadBinaryProto(env, filename, &snapshot);
  + if (s.ok()) {
  return snapshot;
  }
  + if (s.code() == tensorflow::error::NOT_FOUND) {
  + return s;
  + }
  CHECK(opts.use_fake_data)
  << "Without --use_fake_data, you must pass an HloSnapshot -- HloProto "
  "and textual HLO don't carry real data.";
  @@ -258,6 +262,9 @@ int RealMain(tensorflow::gtl::ArraySlice<char*> args, const Options& opts) {
  StatusOr<HloSnapshot> maybe_snapshot = ParseInputFile(arg, opts);
  if (maybe_snapshot.ok()) {
  snapshots.push_back(std::move(maybe_snapshot).ValueOrDie());
  + } else {
  + LOG(ERROR) << "Can't handle file " << arg << ": "
  + << maybe_snapshot.status();
  }
  }
  