Add runtime option for forcing error if poetry is not found

tox_poetry_installer/_poetry.py

@@ -36,6 +36,5 @@ try:
     from poetry.utils.env import VirtualEnv
 except ImportError:
     raise exceptions.PoetryNotInstalledError(
-        f"No version of Poetry could be imported under the current environment for '{sys.executable}'",
-        sys.path,
+        f"No version of Poetry could be imported under the current environment for '{sys.executable}'"
     ) from None

tox_poetry_installer/hooks.py

@@ -29,6 +29,13 @@ def tox_addoption(parser: ToxParser):
     dependencies should be treated as locked or not.
     """
 
+    parser.add_argument(
+        "--require-poetry",
+        action="store_true",
+        dest="require_poetry",
+        help="Trigger a failure if Poetry is not available to Tox",
+    )
+
     parser.add_testenv_attribute(
         name="install_dev_deps",
         type="bool",
@@ -65,6 +72,13 @@ def tox_testenv_install_deps(venv: ToxVirtualEnv, action: ToxAction) -> Optional
     try:
         poetry = utilities.check_preconditions(venv, action)
     except exceptions.SkipEnvironment as err:
+        if (
+            isinstance(err, exceptions.PoetryNotInstalledError)
+            and venv.envconfig.config.option.require_poetry
+        ):
+            venv.status = err.__class__.__name__
+            reporter.error(str(err))
+            return False
         reporter.verbosity1(str(err))
         return None
 

tox_poetry_installer/utilities.py

@@ -114,8 +114,6 @@ def find_transients(packages: PackageMap, dependency_name: str) -> Set[PoetryPac
 
 def check_preconditions(venv: ToxVirtualEnv, action: ToxAction) -> "_poetry.Poetry":
     """Check that the local project environment meets expectations"""
-    from tox_poetry_installer import _poetry
-
     # Skip running the plugin for the packaging environment. PEP-517 front ends can handle
     # that better than we can, so let them do their thing. More to the point: if you're having
     # problems in the packaging env that this plugin would solve, god help you.
@@ -124,6 +122,8 @@ def check_preconditions(venv: ToxVirtualEnv, action: ToxAction) -> "_poetry.Poet
             f"Skipping isolated packaging build env '{action.name}'"
         )
 
+    from tox_poetry_installer import _poetry
+
     try:
         return _poetry.Factory().create_poetry(venv.envconfig.config.toxinidir)
     # Support running the plugin when the current tox project does not use Poetry for its