We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Add more details to Callback doc
(from zulip chat)
> When are the Callbacks executed in the hydra stack exactly? More specifically, are they executed after the launchers in the environments that the launchers provide? (Would be awesome to add a sentence about this in the docs)


--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `hydra/experimental/callback.py`
Content:
```
1 # Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
2 import logging
3 from typing import Any
4 
5 from omegaconf import DictConfig
6 
7 from hydra.core.utils import JobReturn
8 
9 logger = logging.getLogger(__name__)
10 
11 
12 class Callback:
13     def on_run_start(self, config: DictConfig, **kwargs: Any) -> None:
14         """
15         Called in RUN mode before job starts.
16         """
17         ...
18 
19     def on_run_end(self, config: DictConfig, **kwargs: Any) -> None:
20         """
21         Called in RUN mode after job ends.
22         """
23         ...
24 
25     def on_multirun_start(self, config: DictConfig, **kwargs: Any) -> None:
26         """
27         Called in MULTIRUN mode before any job starts.
28         """
29         ...
30 
31     def on_multirun_end(self, config: DictConfig, **kwargs: Any) -> None:
32         """
33         Called in MULTIRUN mode after all jobs end.
34         """
35         ...
36 
37     def on_job_start(self, config: DictConfig, **kwargs: Any) -> None:
38         """
39         Called in both RUN and MULTIRUN modes, once for each Hydra job (before running
40         application code).
41         """
42         ...
43 
44     def on_job_end(
45         self, config: DictConfig, job_return: JobReturn, **kwargs: Any
46     ) -> None:
47         """
48         Called in both RUN and MULTIRUN modes, once for each Hydra job (after running
49         application code).
50         """
51         ...
52
```
--- 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/hydra/experimental/callback.py b/hydra/experimental/callback.py
--- a/hydra/experimental/callback.py
+++ b/hydra/experimental/callback.py
@@ -12,32 +12,37 @@
 class Callback:
     def on_run_start(self, config: DictConfig, **kwargs: Any) -> None:
         """
-        Called in RUN mode before job starts.
+        Called in RUN mode before job/application code starts. `config` is composed with overrides.
+        Some `hydra.runtime` configs are not populated yet.
+        See hydra.core.utils.run_job for more info.
         """
         ...
 
     def on_run_end(self, config: DictConfig, **kwargs: Any) -> None:
         """
-        Called in RUN mode after job ends.
+        Called in RUN mode after job/application code returns.
         """
         ...
 
     def on_multirun_start(self, config: DictConfig, **kwargs: Any) -> None:
         """
         Called in MULTIRUN mode before any job starts.
+        When using a launcher, this will be executed on local machine before any Sweeper/Launcher is initialized.
         """
         ...
 
     def on_multirun_end(self, config: DictConfig, **kwargs: Any) -> None:
         """
-        Called in MULTIRUN mode after all jobs end.
+        Called in MULTIRUN mode after all jobs returns.
+        When using a launcher, this will be executed on local machine.
         """
         ...
 
     def on_job_start(self, config: DictConfig, **kwargs: Any) -> None:
         """
-        Called in both RUN and MULTIRUN modes, once for each Hydra job (before running
-        application code).
+        Called in both RUN and MULTIRUN modes, once for each Hydra job (before running application code).
+        This is called from within `hydra.core.utils.run_job`. In the case of remote launching, this will be executed
+        on the remote server along with your application code.
         """
         ...
 
@@ -47,5 +52,10 @@
         """
         Called in both RUN and MULTIRUN modes, once for each Hydra job (after running
         application code).
+        This is called from within `hydra.core.utils.run_job`. In the case of remote launching, this will be executed
+        on the remote server after your application code.
+
+        `job_return` contains info that could be useful for logging or post-processing.
+        See hydra.core.utils.JobReturn for more.
         """
         ...

{"golden_diff": "diff --git a/hydra/experimental/callback.py b/hydra/experimental/callback.py\n--- a/hydra/experimental/callback.py\n+++ b/hydra/experimental/callback.py\n@@ -12,32 +12,37 @@\n class Callback:\n     def on_run_start(self, config: DictConfig, **kwargs: Any) -> None:\n         \"\"\"\n-        Called in RUN mode before job starts.\n+        Called in RUN mode before job/application code starts. `config` is composed with overrides.\n+        Some `hydra.runtime` configs are not populated yet.\n+        See hydra.core.utils.run_job for more info.\n         \"\"\"\n         ...\n \n     def on_run_end(self, config: DictConfig, **kwargs: Any) -> None:\n         \"\"\"\n-        Called in RUN mode after job ends.\n+        Called in RUN mode after job/application code returns.\n         \"\"\"\n         ...\n \n     def on_multirun_start(self, config: DictConfig, **kwargs: Any) -> None:\n         \"\"\"\n         Called in MULTIRUN mode before any job starts.\n+        When using a launcher, this will be executed on local machine before any Sweeper/Launcher is initialized.\n         \"\"\"\n         ...\n \n     def on_multirun_end(self, config: DictConfig, **kwargs: Any) -> None:\n         \"\"\"\n-        Called in MULTIRUN mode after all jobs end.\n+        Called in MULTIRUN mode after all jobs returns.\n+        When using a launcher, this will be executed on local machine.\n         \"\"\"\n         ...\n \n     def on_job_start(self, config: DictConfig, **kwargs: Any) -> None:\n         \"\"\"\n-        Called in both RUN and MULTIRUN modes, once for each Hydra job (before running\n-        application code).\n+        Called in both RUN and MULTIRUN modes, once for each Hydra job (before running application code).\n+        This is called from within `hydra.core.utils.run_job`. In the case of remote launching, this will be executed\n+        on the remote server along with your application code.\n         \"\"\"\n         ...\n \n@@ -47,5 +52,10 @@\n         \"\"\"\n         Called in both RUN and MULTIRUN modes, once for each Hydra job (after running\n         application code).\n+        This is called from within `hydra.core.utils.run_job`. In the case of remote launching, this will be executed\n+        on the remote server after your application code.\n+\n+        `job_return` contains info that could be useful for logging or post-processing.\n+        See hydra.core.utils.JobReturn for more.\n         \"\"\"\n         ...\n", "issue": "Add more details to Callback doc\n(from zulip chat)\r\n> When are the Callbacks executed in the hydra stack exactly? More specifically, are they executed after the launchers in the environments that the launchers provide? (Would be awesome to add a sentence about this in the docs)\r\n\n", "before_files": [{"content": "# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved\nimport logging\nfrom typing import Any\n\nfrom omegaconf import DictConfig\n\nfrom hydra.core.utils import JobReturn\n\nlogger = logging.getLogger(__name__)\n\n\nclass Callback:\n    def on_run_start(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in RUN mode before job starts.\n        \"\"\"\n        ...\n\n    def on_run_end(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in RUN mode after job ends.\n        \"\"\"\n        ...\n\n    def on_multirun_start(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in MULTIRUN mode before any job starts.\n        \"\"\"\n        ...\n\n    def on_multirun_end(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in MULTIRUN mode after all jobs end.\n        \"\"\"\n        ...\n\n    def on_job_start(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in both RUN and MULTIRUN modes, once for each Hydra job (before running\n        application code).\n        \"\"\"\n        ...\n\n    def on_job_end(\n        self, config: DictConfig, job_return: JobReturn, **kwargs: Any\n    ) -> None:\n        \"\"\"\n        Called in both RUN and MULTIRUN modes, once for each Hydra job (after running\n        application code).\n        \"\"\"\n        ...\n", "path": "hydra/experimental/callback.py"}], "after_files": [{"content": "# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved\nimport logging\nfrom typing import Any\n\nfrom omegaconf import DictConfig\n\nfrom hydra.core.utils import JobReturn\n\nlogger = logging.getLogger(__name__)\n\n\nclass Callback:\n    def on_run_start(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in RUN mode before job/application code starts. `config` is composed with overrides.\n        Some `hydra.runtime` configs are not populated yet.\n        See hydra.core.utils.run_job for more info.\n        \"\"\"\n        ...\n\n    def on_run_end(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in RUN mode after job/application code returns.\n        \"\"\"\n        ...\n\n    def on_multirun_start(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in MULTIRUN mode before any job starts.\n        When using a launcher, this will be executed on local machine before any Sweeper/Launcher is initialized.\n        \"\"\"\n        ...\n\n    def on_multirun_end(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in MULTIRUN mode after all jobs returns.\n        When using a launcher, this will be executed on local machine.\n        \"\"\"\n        ...\n\n    def on_job_start(self, config: DictConfig, **kwargs: Any) -> None:\n        \"\"\"\n        Called in both RUN and MULTIRUN modes, once for each Hydra job (before running application code).\n        This is called from within `hydra.core.utils.run_job`. In the case of remote launching, this will be executed\n        on the remote server along with your application code.\n        \"\"\"\n        ...\n\n    def on_job_end(\n        self, config: DictConfig, job_return: JobReturn, **kwargs: Any\n    ) -> None:\n        \"\"\"\n        Called in both RUN and MULTIRUN modes, once for each Hydra job (after running\n        application code).\n        This is called from within `hydra.core.utils.run_job`. In the case of remote launching, this will be executed\n        on the remote server after your application code.\n\n        `job_return` contains info that could be useful for logging or post-processing.\n        See hydra.core.utils.JobReturn for more.\n        \"\"\"\n        ...\n", "path": "hydra/experimental/callback.py"}]}