We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Cygwin and msys2 bash activator compatibility
**Issue**

Run the following via msys2:

```
$ /c/Users/builder/AppData/Local/Programs/Python/Python39/Scripts/virtualenv.exe --no-pip --no-setuptools --no-wheel -p /c/Users/builder/AppData/Local/Programs/Python/Python39/python.exe /tmp/tmp.uw7eZfvJIO
$ source /tmp/tmp.uw7eZfvJIO/Scripts/activate
$ python
python: command not found
```

The content of `/tmp/tmp.uw7eZfvJIO/Scripts/activate` contains `VIRTUAL_ENV='C:\tools\msys64\tmp\tmp.uw7eZfvJIO'`, but it's expected to be `VIRTUAL_ENV='/c/tools/msys64/tmp/tmp.uw7eZfvJIO'`, thus it can't locate `python`.

I believe the legacy version handles this correctly here: https://github.com/pypa/virtualenv/blob/4c9899f471139670b0f1bfd359c37a67c507447d/virtualenv.py#L1742-L1748

which contains:

`VIRTUAL_ENV="$(if [ "$OSTYPE" "==" "cygwin" ]; then cygpath -u 'C:\tools\msys64\tmp\tmp.uw7eZfvJIO'; else echo '/C/tools/msys64/tmp/tmp.uw7eZfvJIO'; fi;)"`

**Environment**

Provide at least:
- OS: Windows 7, using msys2 v20200903.0.0

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `src/virtualenv/activation/via_template.py`
Content:
```
1 from __future__ import absolute_import, unicode_literals
2 
3 import os
4 import sys
5 from abc import ABCMeta, abstractmethod
6 
7 from six import add_metaclass
8 
9 from virtualenv.util.six import ensure_text
10 
11 from .activator import Activator
12 
13 if sys.version_info >= (3, 7):
14     from importlib.resources import read_binary
15 else:
16     from importlib_resources import read_binary
17 
18 
19 @add_metaclass(ABCMeta)
20 class ViaTemplateActivator(Activator):
21     @abstractmethod
22     def templates(self):
23         raise NotImplementedError
24 
25     def generate(self, creator):
26         dest_folder = creator.bin_dir
27         replacements = self.replacements(creator, dest_folder)
28         generated = self._generate(replacements, self.templates(), dest_folder, creator)
29         if self.flag_prompt is not None:
30             creator.pyenv_cfg["prompt"] = self.flag_prompt
31         return generated
32 
33     def replacements(self, creator, dest_folder):
34         return {
35             "__VIRTUAL_PROMPT__": "" if self.flag_prompt is None else self.flag_prompt,
36             "__VIRTUAL_ENV__": ensure_text(str(creator.dest)),
37             "__VIRTUAL_NAME__": creator.env_name,
38             "__BIN_NAME__": ensure_text(str(creator.bin_dir.relative_to(creator.dest))),
39             "__PATH_SEP__": ensure_text(os.pathsep),
40         }
41 
42     def _generate(self, replacements, templates, to_folder, creator):
43         generated = []
44         for template in templates:
45             text = self.instantiate_template(replacements, template, creator)
46             dest = to_folder / self.as_name(template)
47             # use write_bytes to avoid platform specific line normalization (\n -> \r\n)
48             dest.write_bytes(text.encode("utf-8"))
49             generated.append(dest)
50         return generated
51 
52     def as_name(self, template):
53         return template.name
54 
55     def instantiate_template(self, replacements, template, creator):
56         # read content as binary to avoid platform specific line normalization (\n -> \r\n)
57         binary = read_binary(self.__module__, str(template))
58         text = binary.decode("utf-8", errors="strict")
59         for key, value in replacements.items():
60             value = self._repr_unicode(creator, value)
61             text = text.replace(key, value)
62         return text
63 
64     @staticmethod
65     def _repr_unicode(creator, value):
66         # by default we just let it be unicode
67         return value
68
```
--- 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/src/virtualenv/activation/via_template.py b/src/virtualenv/activation/via_template.py
--- a/src/virtualenv/activation/via_template.py
+++ b/src/virtualenv/activation/via_template.py
@@ -1,7 +1,9 @@
 from __future__ import absolute_import, unicode_literals
 
 import os
+import re
 import sys
+import sysconfig
 from abc import ABCMeta, abstractmethod
 
 from six import add_metaclass
@@ -31,9 +33,17 @@
         return generated
 
     def replacements(self, creator, dest_folder):
+        current_platform = sysconfig.get_platform()
+        platforms = ["mingw", "cygwin", "msys"]
+        if any(platform in current_platform for platform in platforms):
+            pattern = re.compile("^([A-Za-z]):(.*)")
+            match = pattern.match(str(creator.dest))
+            virtual_env = "/" + match.group(1).lower() + match.group(2)
+        else:
+            virtual_env = str(creator.dest)
         return {
             "__VIRTUAL_PROMPT__": "" if self.flag_prompt is None else self.flag_prompt,
-            "__VIRTUAL_ENV__": ensure_text(str(creator.dest)),
+            "__VIRTUAL_ENV__": ensure_text(virtual_env),
             "__VIRTUAL_NAME__": creator.env_name,
             "__BIN_NAME__": ensure_text(str(creator.bin_dir.relative_to(creator.dest))),
             "__PATH_SEP__": ensure_text(os.pathsep),

{"golden_diff": "diff --git a/src/virtualenv/activation/via_template.py b/src/virtualenv/activation/via_template.py\n--- a/src/virtualenv/activation/via_template.py\n+++ b/src/virtualenv/activation/via_template.py\n@@ -1,7 +1,9 @@\n from __future__ import absolute_import, unicode_literals\n \n import os\n+import re\n import sys\n+import sysconfig\n from abc import ABCMeta, abstractmethod\n \n from six import add_metaclass\n@@ -31,9 +33,17 @@\n         return generated\n \n     def replacements(self, creator, dest_folder):\n+        current_platform = sysconfig.get_platform()\n+        platforms = [\"mingw\", \"cygwin\", \"msys\"]\n+        if any(platform in current_platform for platform in platforms):\n+            pattern = re.compile(\"^([A-Za-z]):(.*)\")\n+            match = pattern.match(str(creator.dest))\n+            virtual_env = \"/\" + match.group(1).lower() + match.group(2)\n+        else:\n+            virtual_env = str(creator.dest)\n         return {\n             \"__VIRTUAL_PROMPT__\": \"\" if self.flag_prompt is None else self.flag_prompt,\n-            \"__VIRTUAL_ENV__\": ensure_text(str(creator.dest)),\n+            \"__VIRTUAL_ENV__\": ensure_text(virtual_env),\n             \"__VIRTUAL_NAME__\": creator.env_name,\n             \"__BIN_NAME__\": ensure_text(str(creator.bin_dir.relative_to(creator.dest))),\n             \"__PATH_SEP__\": ensure_text(os.pathsep),\n", "issue": "Cygwin and msys2 bash activator compatibility\n**Issue**\r\n\r\nRun the following via msys2:\r\n\r\n```\r\n$ /c/Users/builder/AppData/Local/Programs/Python/Python39/Scripts/virtualenv.exe --no-pip --no-setuptools --no-wheel -p /c/Users/builder/AppData/Local/Programs/Python/Python39/python.exe /tmp/tmp.uw7eZfvJIO\r\n$ source /tmp/tmp.uw7eZfvJIO/Scripts/activate\r\n$ python\r\npython: command not found\r\n```\r\n\r\nThe content of `/tmp/tmp.uw7eZfvJIO/Scripts/activate` contains `VIRTUAL_ENV='C:\\tools\\msys64\\tmp\\tmp.uw7eZfvJIO'`, but it's expected to be `VIRTUAL_ENV='/c/tools/msys64/tmp/tmp.uw7eZfvJIO'`, thus it can't locate `python`.\r\n\r\nI believe the legacy version handles this correctly here: https://github.com/pypa/virtualenv/blob/4c9899f471139670b0f1bfd359c37a67c507447d/virtualenv.py#L1742-L1748\r\n\r\nwhich contains:\r\n\r\n`VIRTUAL_ENV=\"$(if [ \"$OSTYPE\" \"==\" \"cygwin\" ]; then cygpath -u 'C:\\tools\\msys64\\tmp\\tmp.uw7eZfvJIO'; else echo '/C/tools/msys64/tmp/tmp.uw7eZfvJIO'; fi;)\"`\r\n\r\n**Environment**\r\n\r\nProvide at least:\r\n- OS: Windows 7, using msys2 v20200903.0.0\n", "before_files": [{"content": "from __future__ import absolute_import, unicode_literals\n\nimport os\nimport sys\nfrom abc import ABCMeta, abstractmethod\n\nfrom six import add_metaclass\n\nfrom virtualenv.util.six import ensure_text\n\nfrom .activator import Activator\n\nif sys.version_info >= (3, 7):\n    from importlib.resources import read_binary\nelse:\n    from importlib_resources import read_binary\n\n\n@add_metaclass(ABCMeta)\nclass ViaTemplateActivator(Activator):\n    @abstractmethod\n    def templates(self):\n        raise NotImplementedError\n\n    def generate(self, creator):\n        dest_folder = creator.bin_dir\n        replacements = self.replacements(creator, dest_folder)\n        generated = self._generate(replacements, self.templates(), dest_folder, creator)\n        if self.flag_prompt is not None:\n            creator.pyenv_cfg[\"prompt\"] = self.flag_prompt\n        return generated\n\n    def replacements(self, creator, dest_folder):\n        return {\n            \"__VIRTUAL_PROMPT__\": \"\" if self.flag_prompt is None else self.flag_prompt,\n            \"__VIRTUAL_ENV__\": ensure_text(str(creator.dest)),\n            \"__VIRTUAL_NAME__\": creator.env_name,\n            \"__BIN_NAME__\": ensure_text(str(creator.bin_dir.relative_to(creator.dest))),\n            \"__PATH_SEP__\": ensure_text(os.pathsep),\n        }\n\n    def _generate(self, replacements, templates, to_folder, creator):\n        generated = []\n        for template in templates:\n            text = self.instantiate_template(replacements, template, creator)\n            dest = to_folder / self.as_name(template)\n            # use write_bytes to avoid platform specific line normalization (\\n -> \\r\\n)\n            dest.write_bytes(text.encode(\"utf-8\"))\n            generated.append(dest)\n        return generated\n\n    def as_name(self, template):\n        return template.name\n\n    def instantiate_template(self, replacements, template, creator):\n        # read content as binary to avoid platform specific line normalization (\\n -> \\r\\n)\n        binary = read_binary(self.__module__, str(template))\n        text = binary.decode(\"utf-8\", errors=\"strict\")\n        for key, value in replacements.items():\n            value = self._repr_unicode(creator, value)\n            text = text.replace(key, value)\n        return text\n\n    @staticmethod\n    def _repr_unicode(creator, value):\n        # by default we just let it be unicode\n        return value\n", "path": "src/virtualenv/activation/via_template.py"}], "after_files": [{"content": "from __future__ import absolute_import, unicode_literals\n\nimport os\nimport re\nimport sys\nimport sysconfig\nfrom abc import ABCMeta, abstractmethod\n\nfrom six import add_metaclass\n\nfrom virtualenv.util.six import ensure_text\n\nfrom .activator import Activator\n\nif sys.version_info >= (3, 7):\n    from importlib.resources import read_binary\nelse:\n    from importlib_resources import read_binary\n\n\n@add_metaclass(ABCMeta)\nclass ViaTemplateActivator(Activator):\n    @abstractmethod\n    def templates(self):\n        raise NotImplementedError\n\n    def generate(self, creator):\n        dest_folder = creator.bin_dir\n        replacements = self.replacements(creator, dest_folder)\n        generated = self._generate(replacements, self.templates(), dest_folder, creator)\n        if self.flag_prompt is not None:\n            creator.pyenv_cfg[\"prompt\"] = self.flag_prompt\n        return generated\n\n    def replacements(self, creator, dest_folder):\n        current_platform = sysconfig.get_platform()\n        platforms = [\"mingw\", \"cygwin\", \"msys\"]\n        if any(platform in current_platform for platform in platforms):\n            pattern = re.compile(\"^([A-Za-z]):(.*)\")\n            match = pattern.match(str(creator.dest))\n            virtual_env = \"/\" + match.group(1).lower() + match.group(2)\n        else:\n            virtual_env = str(creator.dest)\n        return {\n            \"__VIRTUAL_PROMPT__\": \"\" if self.flag_prompt is None else self.flag_prompt,\n            \"__VIRTUAL_ENV__\": ensure_text(virtual_env),\n            \"__VIRTUAL_NAME__\": creator.env_name,\n            \"__BIN_NAME__\": ensure_text(str(creator.bin_dir.relative_to(creator.dest))),\n            \"__PATH_SEP__\": ensure_text(os.pathsep),\n        }\n\n    def _generate(self, replacements, templates, to_folder, creator):\n        generated = []\n        for template in templates:\n            text = self.instantiate_template(replacements, template, creator)\n            dest = to_folder / self.as_name(template)\n            # use write_bytes to avoid platform specific line normalization (\\n -> \\r\\n)\n            dest.write_bytes(text.encode(\"utf-8\"))\n            generated.append(dest)\n        return generated\n\n    def as_name(self, template):\n        return template.name\n\n    def instantiate_template(self, replacements, template, creator):\n        # read content as binary to avoid platform specific line normalization (\\n -> \\r\\n)\n        binary = read_binary(self.__module__, str(template))\n        text = binary.decode(\"utf-8\", errors=\"strict\")\n        for key, value in replacements.items():\n            value = self._repr_unicode(creator, value)\n            text = text.replace(key, value)\n        return text\n\n    @staticmethod\n    def _repr_unicode(creator, value):\n        # by default we just let it be unicode\n        return value\n", "path": "src/virtualenv/activation/via_template.py"}]}