Exception in device=TPU:1: 'ascii' codec can't decode byte 0xc2 in position 37: ordinal not in range(128)
I get the error message when trying to run the seq2seq example on 8 TPU cores on XSUM and bart-large.

Run this from `examples/seq2seq`:
```
export PYTHONPATH="../":"${PYTHONPATH}"

python finetune.py \
    --learning_rate=3e-5 \
    --gpus 0 \
    --n_tpu_cores 8 \
    --do_train \
    --do_predict \
    --n_val 1000 \
    --val_check_interval 1.0 \
    --sortish_sampler \
    --data_dir ${PWD}/xsum \
    --train_batch_size=1 \
    --eval_batch_size=1 \
    --output_dir=xsum_results \
    --num_train_epochs 1 \
    --model_name_or_path facebook/bart-large
```

BTW there is also a bug in `lightning_base.py`. The `gpus` argument is given twice if `n_tpu_cores` is specified (second time through `**train_params`) so I replaced Trainer creation lines with these:
```
    n_gpus = train_params.pop("gpus", args.gpus)

    trainer = pl.Trainer(
        logger=logger,
        accumulate_grad_batches=args.gradient_accumulation_steps,
        gpus=n_gpus,
        max_epochs=args.num_train_epochs,
        early_stop_callback=early_stopping_callback,
        gradient_clip_val=args.max_grad_norm,
        checkpoint_callback=checkpoint_callback,
        callbacks=[logging_callback] + extra_callbacks,
        fast_dev_run=args.fast_dev_run,
        val_check_interval=args.val_check_interval,
        weights_summary=None,
        resume_from_checkpoint=args.resume_from_checkpoint,
        **train_params,
    )
```
...it also happens on CPU<|||||>I solved it. If you happen to use a Google Cloud VM with the `Debian GNU/Linux 9 Stretch + PyTorch/XLA` image then locale is not set correctly. Add the following to `/etc/default/locale`:
```
LC_ALL=en_US.UTF-8
```<|||||>...thank you, it works!