(debugging_environment_variables)=
# Debugging Environment Variables

:::{list-table}
  :header-rows: 1

  * - Variable
    - Description
  * - ``TORCH_SHOW_CPP_STACKTRACES``
    - If set to ``1``, makes PyTorch print out a stack trace when it detects a C++ error.
  * - ``TORCH_CPP_LOG_LEVEL``
    - Set the log level of c10 logging facility (supports both GLOG and c10 loggers). Valid values are ``INFO``, ``WARNING``, ``ERROR``, and ``FATAL`` or their numerical equivalents ``0``, ``1``, ``2``, and ``3``.
  * - ``TORCH_LOGS``
    -  For a more in depth explanation of this environment variable, see {doc}`/logging`.
  * - ``TORCH_DIST_NAN_CHECK``
    - If set to ``1``, checks the input (send) buffers of every ``torch.distributed`` collective for NaNs, for any backend. Unlike ``TORCH_NCCL_NAN_CHECK``, which is implemented natively by the NCCL backend, this is driven by the backend-agnostic ``ProcessGroup`` collective hooks.