Calling fit mutiple times fails to call teardown
🐛When calling fit mutiple times teardown(self, stage), on_train_end(self) are called mutiple times
Please reproduce using the BoringModel
If your create a new teacher instance everything works great but if you dont it fails.
Here is the colab to reproduce the error:
https://colab.research.google.com/drive/1G6korxcAO12wXLwhCMxTHkG3-bjMnfsc?usp=sharing

PyTorch Version (e.g., 1.0): 1.7
OS (e.g., Linux): Linux
How you installed PyTorch (conda, pip, source): conda
Build command you used (if compiling from source):
Python version: 3.7.6
CUDA/cuDNN version: CUDA 10.2 Driver Version: 440.100
GPU models and configuration: 2080Ti and 1080Ti also 4x2080Ti DDP