Fix cygwin NoneType error if POSIX path in dest (#1964)

Closes #1962. Corrects an AttributeError for a regex match not
found if the cygwin path is already in posix format.

docs/changelog/1962.bugfix.rst

@@ -0,0 +1 @@
+Fix Nonetype error in cygwin if POSIX path in dest - by :user:`danyeaw`.

src/virtualenv/activation/via_template.py

@@ -38,7 +38,10 @@ def replacements(self, creator, dest_folder):
  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)
+ if match:
+ virtual_env = "/" + match.group(1).lower() + match.group(2)
+ else:
+ virtual_env = str(creator.dest)
  else:
  virtual_env = str(creator.dest)
  return {

tests/unit/activation/test_activation_support.py

@@ -84,3 +84,16 @@ def test_win_path_no_conversion(mocker, activator_class):
  mocker.stub(creator.bin_dir.relative_to)
  resource = activator.replacements(creator, "")
  assert resource["__VIRTUAL_ENV__"] == "C:/tools/msys64/home"
+
+
+@pytest.mark.skipif(IS_WIN, reason="Github Actions ships with WSL bash")
+@pytest.mark.parametrize("activator_class", [BashActivator])
+def test_cygwin_path_no_conversion(mocker, activator_class):
+ mocker.patch("sysconfig.get_platform", return_value="cygwin")
+ activator = activator_class(Namespace(prompt=None))
+ creator = Creator()
+ creator.dest = "/c/tools/msys64/home"
+ creator.bin_dir = Path("/c/tools/msys64/home/bin")
+ mocker.stub(creator.bin_dir.relative_to)
+ resource = activator.replacements(creator, "")
+ assert resource["__VIRTUAL_ENV__"] == "/c/tools/msys64/home"