We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
an error importing AMP in fairscale when using a Pytorch version less than 1.6
## 🐛 Bug

<!-- A clear and concise description of what the bug is. -->

## Command

## To Reproduce

<img width="737" alt="Screenshot 2020-11-23 at 08 21 28" src="https://user-images.githubusercontent.com/12861981/99949945-c2f11300-2d73-11eb-87f2-17a02e64da75.png">


Steps to reproduce the behavior:

<!-- If you were running a command, post the exact command that you were running -->

1.
2.
3.

<!-- If you have a code sample, error messages, stack traces, please provide it here as well -->

## Expected behavior

<!-- A clear and concise description of what you expected to happen. -->

## Environment

Please copy and paste the output from the
environment collection script from PyTorch
(or fill out the checklist below manually).

You can run the script with:
```
# For security purposes, please check the contents of collect_env.py before running it.
python -m torch.utils.collect_env
```

 - PyTorch Version (e.g., 1.0):
 - OS (e.g., Linux):
 - How you installed PyTorch (`conda`, `pip`, source):
 - Build command you used (if compiling from source):
 - Python version:
 - CUDA/cuDNN version:
 - GPU models and configuration:
 - Any other relevant information:

## Additional context

<!-- Add any other context about the problem here. -->


--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `fairscale/optim/__init__.py`
Content:
```
1 # Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
2 #
3 # This source code is licensed under the BSD license found in the
4 # LICENSE file in the root directory of this source tree.
5 
6 """
7 :mod:`fairscale.optim` is a package implementing various torch optimization algorithms.
8 """
9 
10 try:
11     from .adam import Adam, Precision
12 except ImportError:  # pragma: no cover
13     pass  # pragma: no cover
14 from .adascale import AdaScale
15 from .grad_scaler import GradScaler
16 from .oss import OSS
17
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/fairscale/optim/__init__.py b/fairscale/optim/__init__.py
--- a/fairscale/optim/__init__.py
+++ b/fairscale/optim/__init__.py
@@ -6,11 +6,16 @@
 """
 :mod:`fairscale.optim` is a package implementing various torch optimization algorithms.
 """
+import logging
+
+from .adascale import AdaScale
+from .oss import OSS
 
 try:
     from .adam import Adam, Precision
 except ImportError:  # pragma: no cover
     pass  # pragma: no cover
-from .adascale import AdaScale
-from .grad_scaler import GradScaler
-from .oss import OSS
+try:
+    from .grad_scaler import GradScaler
+except ImportError:
+    logging.warning("Torch AMP is not available on this platform")

{"golden_diff": "diff --git a/fairscale/optim/__init__.py b/fairscale/optim/__init__.py\n--- a/fairscale/optim/__init__.py\n+++ b/fairscale/optim/__init__.py\n@@ -6,11 +6,16 @@\n \"\"\"\n :mod:`fairscale.optim` is a package implementing various torch optimization algorithms.\n \"\"\"\n+import logging\n+\n+from .adascale import AdaScale\n+from .oss import OSS\n \n try:\n     from .adam import Adam, Precision\n except ImportError:  # pragma: no cover\n     pass  # pragma: no cover\n-from .adascale import AdaScale\n-from .grad_scaler import GradScaler\n-from .oss import OSS\n+try:\n+    from .grad_scaler import GradScaler\n+except ImportError:\n+    logging.warning(\"Torch AMP is not available on this platform\")\n", "issue": "an error importing AMP in fairscale when using a Pytorch version less than 1.6\n## \ud83d\udc1b Bug\r\n\r\n<!-- A clear and concise description of what the bug is. -->\r\n\r\n## Command\r\n\r\n## To Reproduce\r\n\r\n<img width=\"737\" alt=\"Screenshot 2020-11-23 at 08 21 28\" src=\"https://user-images.githubusercontent.com/12861981/99949945-c2f11300-2d73-11eb-87f2-17a02e64da75.png\">\r\n\r\n\r\nSteps to reproduce the behavior:\r\n\r\n<!-- If you were running a command, post the exact command that you were running -->\r\n\r\n1.\r\n2.\r\n3.\r\n\r\n<!-- If you have a code sample, error messages, stack traces, please provide it here as well -->\r\n\r\n## Expected behavior\r\n\r\n<!-- A clear and concise description of what you expected to happen. -->\r\n\r\n## Environment\r\n\r\nPlease copy and paste the output from the\r\nenvironment collection script from PyTorch\r\n(or fill out the checklist below manually).\r\n\r\nYou can run the script with:\r\n```\r\n# For security purposes, please check the contents of collect_env.py before running it.\r\npython -m torch.utils.collect_env\r\n```\r\n\r\n - PyTorch Version (e.g., 1.0):\r\n - OS (e.g., Linux):\r\n - How you installed PyTorch (`conda`, `pip`, source):\r\n - Build command you used (if compiling from source):\r\n - Python version:\r\n - CUDA/cuDNN version:\r\n - GPU models and configuration:\r\n - Any other relevant information:\r\n\r\n## Additional context\r\n\r\n<!-- Add any other context about the problem here. -->\r\n\n", "before_files": [{"content": "# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.\n#\n# This source code is licensed under the BSD license found in the\n# LICENSE file in the root directory of this source tree.\n\n\"\"\"\n:mod:`fairscale.optim` is a package implementing various torch optimization algorithms.\n\"\"\"\n\ntry:\n    from .adam import Adam, Precision\nexcept ImportError:  # pragma: no cover\n    pass  # pragma: no cover\nfrom .adascale import AdaScale\nfrom .grad_scaler import GradScaler\nfrom .oss import OSS\n", "path": "fairscale/optim/__init__.py"}], "after_files": [{"content": "# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.\n#\n# This source code is licensed under the BSD license found in the\n# LICENSE file in the root directory of this source tree.\n\n\"\"\"\n:mod:`fairscale.optim` is a package implementing various torch optimization algorithms.\n\"\"\"\nimport logging\n\nfrom .adascale import AdaScale\nfrom .oss import OSS\n\ntry:\n    from .adam import Adam, Precision\nexcept ImportError:  # pragma: no cover\n    pass  # pragma: no cover\ntry:\n    from .grad_scaler import GradScaler\nexcept ImportError:\n    logging.warning(\"Torch AMP is not available on this platform\")\n", "path": "fairscale/optim/__init__.py"}]}