message: Fix a bug in dynamic kernel loader.
  if an environment variable is not set, getenv returns nullptr. Check that
  before running strcmp.
diff: @@ -1135,8 +1135,11 @@ void LoadDynamicKernelsInternal() {
  // Override to allow loading unsafe packages for development.
  // DO NOT USE UNLESS YOU KNOW WHAT ABI ISSUES YOU CAN ENCOUNTER.
  - bool override_abi_check =
  - strcmp(getenv("TF_REALLY_LOAD_UNSAFE_PACKAGES"), "1") == 0;
  + char* _abi_check_env_var = getenv("TF_REALLY_LOAD_UNSAFE_PACKAGES");
  + bool override_abi_check = false;
  + if (_abi_check_env_var != nullptr) {
  + override_abi_check = strcmp(_abi_check_env_var, "1") == 0;
  + }
  string bazel_kernel_dir =
  io::JoinPath(env->GetRunfilesDir(), "tensorflow", "core", "kernels");
  