fix: expose part deps in PartInfo

This lets the plugin inspect the part's dependencies when determining the
build-packages.

Fixes #911

.bumpversion.cfg

@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 2.1.3
+current_version = 2.1.4
 commit = True
 tag = True
 

craft_parts/__init__.py

@@ -16,7 +16,7 @@
 
 """Craft a project from several parts."""
 
-__version__ = "2.1.3"
+__version__ = "2.1.4"
 
 from . import plugins
 from .actions import Action, ActionProperties, ActionType

craft_parts/infos.py

@@ -19,6 +19,7 @@
 import logging
 import platform
 import re
+from collections.abc import Sequence
 from pathlib import Path
 from typing import TYPE_CHECKING, Any
 
@@ -375,6 +376,7 @@ def __init__(
         self._part_install_dir = part.part_install_dir
         self._part_state_dir = part.part_state_dir
         self._part_cache_dir = part.part_cache_dir
+        self._part_dependencies = part.dependencies
         self.build_attributes = part.spec.build_attributes.copy()
 
     def __getattr__(self, name: str) -> Any:  # noqa: ANN401
@@ -430,6 +432,11 @@ def part_cache_dir(self) -> Path:
         """Return the subdirectory containing this part's cache directory."""
         return self._part_cache_dir
 
+    @property
+    def part_dependencies(self) -> Sequence[str]:
+        """Return the names of the parts that this part depends on."""
+        return self._part_dependencies
+
     def set_project_var(
         self, name: str, value: str, *, raw_write: bool = False
     ) -> None:

craft_parts/plugins/poetry_plugin.py

@@ -90,7 +90,7 @@ def get_build_packages(self) -> set[str]:
         build_packages = super().get_build_packages()
         if (
             not self._system_has_poetry()
-            and "poetry-deps" not in self._part_info.dependencies
+            and "poetry-deps" not in self._part_info.part_dependencies
         ):
             build_packages |= {"python3-poetry"}
         return build_packages

docs/changelog.rst

@@ -2,6 +2,16 @@
 Changelog
 *********
 
+2.1.4 (2024-12-04)
+------------------
+
+Bug fixes:
+
+- Fix a regression where trying to use the poetry plugin without poetry
+  installed on the system would give an error.
+
+For a complete list of commits, check out the `2.1.4`_ release on GitHub.
+
 2.1.3 (2024-11-20)
 ------------------
 
@@ -603,3 +613,4 @@ Bug fixes:
 .. _Poetry: https://python-poetry.org
 
 .. _2.1.3: https://github.com/canonical/craft-parts/releases/tag/2.1.3
+.. _2.1.4: https://github.com/canonical/craft-parts/releases/tag/2.1.4

setup.py

@@ -21,7 +21,7 @@
 
 from setuptools import find_packages, setup
 
-VERSION = "2.1.3"
+VERSION = "2.1.4"
 
 with open("README.md") as readme_file:
     readme = readme_file.read()

tests/unit/plugins/test_poetry_plugin.py

@@ -34,21 +34,29 @@ def plugin(new_dir):
 
 
 @pytest.mark.parametrize(
-    ("has_poetry", "part_deps", "expected_packages"),
+    ("has_poetry", "part_deps", "expected_added_poetry"),
     [
-        (False, set(), {"python3-poetry"}),
-        (False, {"poetry-deps"}, set()),
-        (True, {"poetry-deps"}, set()),
-        (True, set(), set()),
+        (False, set(), True),
+        (False, {"poetry-deps"}, False),
+        (True, {"poetry-deps"}, False),
+        (True, set(), False),
     ],
 )
 def test_get_build_packages(
-    monkeypatch, plugin: PoetryPlugin, has_poetry, part_deps, expected_packages: set
+    monkeypatch,
+    plugin: PoetryPlugin,
+    has_poetry,
+    part_deps,
+    expected_added_poetry,
 ):
     monkeypatch.setattr(plugin, "_system_has_poetry", lambda: has_poetry)
-    plugin._part_info.dependencies = part_deps  # type: ignore[attr-defined]
+    plugin._part_info._part_dependencies = part_deps
+    assert plugin._part_info.part_dependencies == part_deps
 
-    assert plugin.get_build_packages().issuperset(expected_packages)
+    obtained = plugin.get_build_packages()
+    added_poetry = "python3-poetry" in obtained
+
+    assert added_poetry == expected_added_poetry
 
 
 def test_get_build_environment(plugin, new_dir):

tests/unit/test_infos.py

@@ -485,6 +485,13 @@ def test_part_info_get_project_var():
     )
 
 
+def test_part_info_part_dependencies():
+    info = ProjectInfo(application_name="test", cache_dir=Path())
+    part = Part("foo", {"after": ["part1", "part2"]})
+    x = PartInfo(project_info=info, part=part)
+    assert x.part_dependencies == ["part1", "part2"]
+
+
 def test_step_info(new_dir):
     info = ProjectInfo(
         application_name="test",