Skip PoetryExecutor if poetry is not found

poethepoet/executor/base.py

@@ -69,6 +69,10 @@ def __init__(
         self.capture_stdout = capture_stdout
         self._is_windows = sys.platform == "win32"
 
+    @classmethod
+    def fits_in(cls, context: "RunContext") -> bool:
+        return True
+
     @classmethod
     def get(
         cls,
@@ -96,7 +100,6 @@ def _resolve_implementation(
         by making some reasonable assumptions based on visible features of the
         environment
         """
-        from ..virtualenv import Virtualenv
 
         config_executor_type = context.executor_type
         if executor_config:
@@ -106,13 +109,13 @@ def _resolve_implementation(
                 )
             return cls.__executor_types[executor_config["type"]]
         elif config_executor_type == "auto":
-            if "poetry" in context.config.project["tool"]:
-                # Looks like this is a poetry project!
-                return cls.__executor_types["poetry"]
+            for impl in [
+                cls.__executor_types["poetry"],
+                cls.__executor_types["virtualenv"],
+            ]:
+                if impl.fits_in(context):
+                    return impl
 
-            if Virtualenv.detect(context.project_dir):
-                # Looks like there's a local virtualenv
-                return cls.__executor_types["virtualenv"]
             # Fallback to not using any particular environment
             return cls.__executor_types["simple"]
         else:

poethepoet/executor/poetry.py

@@ -1,10 +1,13 @@
 from os import environ
 from pathlib import Path
-from typing import Dict, Optional, Sequence, Type
+from typing import TYPE_CHECKING, Dict, Optional, Sequence, Type
 
 from ..exceptions import PoeException
 from .base import PoeExecutor
 
+if TYPE_CHECKING:
+    from ..context import RunContext
+
 
 class PoetryExecutor(PoeExecutor):
     """
@@ -15,6 +18,12 @@ class PoetryExecutor(PoeExecutor):
     __key__ = "poetry"
     __options__: Dict[str, Type] = {}
 
+    @classmethod
+    def fits_in(cls, context: "RunContext") -> bool:
+        if "poetry" not in context.config.project["tool"]:
+            return False
+        return cls._poetry_cmd_from_path()
+
     def execute(
         self, cmd: Sequence[str], input: Optional[bytes] = None, use_exec: bool = False
     ) -> int:
@@ -90,15 +99,20 @@ def _get_poetry_virtualenv(self, force: bool = True):
 
         return exec_cache.get("poetry_virtualenv")
 
-    def _poetry_cmd(self):
-        import shutil
-
-        from_path = shutil.which("poetry")
+    @classmethod
+    def _poetry_cmd(cls):
+        from_path = cls._poetry_cmd_from_path()
         if from_path:
             return str(Path(from_path).resolve())
 
         return "poetry"
 
+    @classmethod
+    def _poetry_cmd_from_path(cls):
+        import shutil
+
+        return shutil.which("poetry")
+
     def _virtualenv_creation_disabled(self):
         exec_cache = self.context.exec_cache
 

poethepoet/executor/virtualenv.py

@@ -4,6 +4,7 @@
 from .base import PoeExecutor
 
 if TYPE_CHECKING:
+    from ..context import RunContext
     from ..virtualenv import Virtualenv
 
 
@@ -15,6 +16,12 @@ class VirtualenvExecutor(PoeExecutor):
     __key__ = "virtualenv"
     __options__: Dict[str, Type] = {"location": str}
 
+    @classmethod
+    def fits_in(cls, context: "RunContext") -> bool:
+        from ..virtualenv import Virtualenv
+
+        return Virtualenv.detect(context.project_dir)
+
     def execute(
         self, cmd: Sequence[str], input: Optional[bytes] = None, use_exec: bool = False
     ) -> int: