message: [fuzzer] Debug the monster_tets.bfbs on clusterfuzz server
  For some reason, this fuzzer failed to load the binary schema file
  when run on the `/clusterfuzz` server.
  Issue:
  This issue doesn't reproduce locally with the latest oss-fuzz docker image.
diff: #include <stdint.h>
  #include <clocale>
  +#include <filesystem>
  #include <string>
  #include "cpp17/generated_cpp17/monster_test_generated.h"
  @@ -33,14 +34,31 @@ static constexpr uint8_t flags_strict_json = 0x80;
  static constexpr uint8_t flags_skip_unexpected_fields_in_json = 0x40;
  static constexpr uint8_t flags_allow_non_utf8 = 0x20;
  +bool TestFileExists(const char *file_name) {
  + namespace fs = std::filesystem;
  + const bool file_exists = flatbuffers::FileExists(file_name);
  + TEST_OUTPUT_LINE("@DEBUG: test file, exists: %d, name:'%s'", file_exists,
  + file_name);
  + if (file_exists) return true;
  +
  + const auto cwd = fs::current_path();
  + TEST_OUTPUT_LINE("@DEBUG: file '%s' not found with flatbuffers::FileExists()",
  + file_name);
  + TEST_OUTPUT_LINE("@DEBUG: CWD: '%s', fs::exists: %d", cwd.c_str(),
  + fs::exists(cwd / file_name));
  + for (const auto &entry : fs::directory_iterator(cwd)) {
  + TEST_OUTPUT_LINE("@DEBUG: CWD entry: '%s'", entry.path().c_str());
  + }
  + return false;
  +}
  +
  std::string LoadBinarySchema(const char *file_name) {
  + TEST_EQ(true, TestFileExists(file_name));
  std::string schemafile;
  - TEST_EQ(true,
  - flatbuffers::LoadFile(file_name, true, &schemafile));
  + TEST_EQ(true, flatbuffers::LoadFile(file_name, true, &schemafile));
  flatbuffers::Verifier verifier(
  - reinterpret_cast<const uint8_t *>(schemafile.c_str()),
  - schemafile.size());
  + reinterpret_cast<const uint8_t *>(schemafile.c_str()), schemafile.size());
  TEST_EQ(true, reflection::VerifySchemaBuffer(verifier));
  return schemafile;
  }
  @@ -48,7 +66,7 @@ std::string LoadBinarySchema(const char *file_name) {
  std::string do_test(const flatbuffers::IDLOptions &opts,
  const std::string input_json) {
  // once loaded from disk
  - static const std::string schemafile = LoadBinarySchema("./monster_test.bfbs");
  + static const std::string schemafile = LoadBinarySchema("monster_test.bfbs");
  // parse schema first, so we can use it to parse the data after
  flatbuffers::Parser parser;
  TEST_EQ(true, parser.Deserialize(
  