message: test: fix nullptr dereference.
diff: @@ -36,13 +36,13 @@ namespace {
  std::string makeTempDir(char* name_template) {
  #ifdef WIN32
  char* dirname = ::_mktemp(name_template);
  - RELEASE_ASSERT(dirname != nullptr,
  - fmt::format("failed to create tempdir: {} {}", dirname, strerror(errno)));
  + RELEASE_ASSERT(dirname != nullptr, fmt::format("failed to create tempdir from template: {} {}",
  + name_template, strerror(errno)));
  std::experimental::filesystem::create_directories(dirname);
  #else
  char* dirname = ::mkdtemp(name_template);
  - RELEASE_ASSERT(dirname != nullptr,
  - fmt::format("failed to create tempdir: {} {}", dirname, strerror(errno)));
  + RELEASE_ASSERT(dirname != nullptr, fmt::format("failed to create tempdir from template: {} {}",
  + name_template, strerror(errno)));
  #endif
  return std::string(dirname);
  }
  