Fix errors due to venv modifications (PR #7298)

# Description

Fix issues introduced when modifying the PythonEnvironment class during #7107

# Self Check:

Strike through any lines that are not applicable (`~~line~~`) then check the box

- [ ] Attached issue to pull request
- [x] Changelog entry
- [ ] Type annotations are present
- [ ] Code is clear and sufficiently documented
- [ ] No (preventable) type errors (check using make mypy or make mypy-diff)
- [x] Sufficient test cases (reproduces the bug/tests the requested feature)
- [ ] Correct, in line with design
- [ ] End user documentation is included or an issue is created for end-user documentation (add ref to issue here: )
- [ ] If this PR fixes a race condition in the test suite, also push the fix to the relevant stable branche(s) (see [test-fixes](https://internal.inmanta.com/development/core/tasks/build-master.html#test-fixes) for more info)

Author: FloLey

changelogs/unreleased/fix-venv-modifications.yml

@@ -0,0 +1,3 @@
+description: Fix errors due to venv modifications
+change-type: patch
+destination-branches: [master]

src/inmanta/env.py

@@ -548,11 +548,14 @@ class PythonEnvironment:
     Inmanta product packages don't change.
     """
 
+    _invalid_chars_in_path_re = re.compile(r'["$`]')
+
     def __init__(self, *, env_path: Optional[str] = None, python_path: Optional[str] = None) -> None:
         if (env_path is None) == (python_path is None):
             raise ValueError("Exactly one of `env_path` and `python_path` needs to be specified")
         self.env_path: str
         self.python_path: str
+        self._parent_python: Optional[str] = None
         if env_path is not None:
             self.env_path = env_path
             self.python_path = self.get_python_path_for_env_path(self.env_path)
@@ -564,9 +567,31 @@ def __init__(self, *, env_path: Optional[str] = None, python_path: Optional[str]
             self.env_path = self.get_env_path_for_python_path(self.python_path)
             if not self.python_path:
                 raise ValueError("The python_path cannot be an empty string.")
+        self.validate_path(self.env_path)
         self.site_packages_dir: str = self.get_site_dir_for_env_path(self.env_path)
         self._path_pth_file = os.path.join(self.site_packages_dir, "inmanta-inherit-from-parent-venv.pth")
 
+    def validate_path(self, path: str) -> None:
+        """
+        The given path is used in the `./bin/activate` file of the created venv without escaping any special characters.
+        As such, we refuse all special characters here that might cause the given path to be interpreted incorrectly:
+
+            * $: Character used for variable expansion in bash strings.
+            * `: Character used to perform command substitution in bash strings.
+            * ": Character that will be interpreted incorrectly as the end of the string.
+
+        :param path: Path to validate.
+        """
+        if not path:
+            raise ValueError("Cannot create virtual environment because the provided path is an empty string.")
+
+        match = PythonEnvironment._invalid_chars_in_path_re.search(path)
+        if match:
+            raise ValueError(
+                f"Cannot create virtual environment because the provided path `{path}` contains an"
+                f" invalid character (`{match.group()}`)."
+            )
+
     @classmethod
     def get_python_path_for_env_path(cls, env_path: str) -> str:
         """
@@ -603,6 +628,7 @@ def init_env(self) -> None:
         """
         Initialize the virtual environment.
         """
+        self._parent_python = sys.executable
         LOGGER.info("Initializing virtual environment at %s", self.env_path)
 
         # check if the virtual env exists
@@ -1171,36 +1197,11 @@ class VirtualEnv(ActiveEnv):
     Creates and uses a virtual environment for this process. This virtualenv inherits from the previously active one.
     """
 
-    _invalid_chars_in_path_re = re.compile(r'["$`]')
-
     def __init__(self, env_path: str) -> None:
         super().__init__(env_path=env_path)
-        self.validate_path(env_path)
         self.env_path: str = env_path
         self.virtual_python: Optional[str] = None
         self._using_venv: bool = False
-        self._parent_python: Optional[str] = None
-
-    def validate_path(self, path: str) -> None:
-        """
-        The given path is used in the `./bin/activate` file of the created venv without escaping any special characters.
-        As such, we refuse all special characters here that might cause the given path to be interpreted incorrectly:
-
-            * $: Character used for variable expansion in bash strings.
-            * `: Character used to perform command substitution in bash strings.
-            * ": Character that will be interpreted incorrectly as the end of the string.
-
-        :param path: Path to validate.
-        """
-        if not path:
-            raise ValueError("Cannot create virtual environment because the provided path is an empty string.")
-
-        match = VirtualEnv._invalid_chars_in_path_re.search(path)
-        if match:
-            raise ValueError(
-                f"Cannot create virtual environment because the provided path `{path}` contains an"
-                f" invalid character (`{match.group()}`)."
-            )
 
     def exists(self) -> bool:
         """

tests/test_env.py

@@ -680,7 +680,7 @@ def test_basic_logging(tmpdir, caplog):
 
         log_sequence = LogSequence(caplog)
         log_sequence.assert_not("inmanta.env", logging.INFO, f"Creating new virtual environment in {env_dir1}")
-        log_sequence.contains("inmanta.env", logging.INFO, f"Using virtual environment at {env_dir1}")
+        log_sequence.contains("inmanta.env", logging.INFO, f"Initializing virtual environment at {env_dir1}")
 
 
 @pytest.mark.slowtest