improvement: poetry package list support for v2 (#7144)

Fixes #7090

## 📝 Summary
Poetry 1.x and 2.x handle the `poetry show` command differently. The
current `PoetryPackageManager` implementation is fine but with the
release of Poetry 2.0 in January the current implementation breaks. This
PR will fix issue #7090 - and as a side benefit - improve the
`PoetryPackageManager` class.

## 🔍 Description of Changes
### Poetry version detection:
The manager now detects the installed Poetry version (1.x vs 2.x) at
runtime.

### Adaptive command generation:
- For Poetry 1.x, use `poetry show --no-dev`.
  - If no dev dependencies exist, this command still succeeds.
- For Poetry 2.x, attempt `poetry show --without dev`.
  - If the command succeeds, we use its output.
- If it fails with `Group(s) not found`, this indicates that no dev
group is defined — in that case, fall back to `poetry show` to capture
all installed packages.

### Fallback behavior:
If version detection or command inference fails for any reason, default
gracefully to poetry show.

This ensures PoetryPackageManager works consistently across Poetry
versions 1.x → 2.x and avoids breaking when no dependency groups are
defined.

## 📋 Checklist

- [x] I have read the [contributor
guidelines](https://github.com/marimo-team/marimo/blob/main/CONTRIBUTING.md).
- [x] For large changes, or changes that affect the public API: this
change was discussed or approved through an issue, on
[Discord](https://marimo.io/discord?ref=pr), or the community
[discussions](https://github.com/marimo-team/marimo/discussions) (Please
provide a link if applicable).
- [x] I have added tests for the changes made.
- [x] I have run the code and verified that it works as expected.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Dylan Madisetti <[email protected]>

Author: 3 people

marimo/_runtime/packages/pypi_package_manager.py

@@ -539,6 +539,16 @@ class PoetryPackageManager(PypiPackageManager):
     name = "poetry"
     docs_url = "https://python-poetry.org/docs/"
 
+    def _get_poetry_version(self) -> int:
+        proc = subprocess.run(
+            ["poetry", "--version"], capture_output=True, text=True
+        )
+        if proc.returncode != 0:
+            return -1  # and raise on the impl side
+        version_str = proc.stdout.split()[-1].strip("()")
+        major, *_ = map(int, version_str.split("."))
+        return major
+
     def install_command(self, package: str, *, upgrade: bool) -> list[str]:
         return [
             "poetry",
@@ -558,6 +568,7 @@ def _list_packages_from_cmd(
     ) -> list[PackageDescription]:
         if not self.is_manager_installed():
             return []
+
         proc = subprocess.run(
             cmd, capture_output=True, text=True, encoding="utf-8"
         )
@@ -580,6 +591,43 @@ def _list_packages_from_cmd(
             )
         return packages
 
+    def _generate_list_packages_cmd(self, version: int) -> list[str]:
+        """Poetry 1.x and 2.x handle the "show" command differently
+        In poetry 1.x, "poetry show --no-dev" works perfectly fine but is deprecated. This
+            shouldn't matter if 1.8.x is still installed.
+        In poetry 2.x the preferred command is "poetry show --without dev" but will throw
+            an error if there are no dev packages installed. We will capture that error and
+            adjust the cmd accordingly.
+        """
+        if version == 1:
+            return ["poetry", "show", "--no-dev"]
+
+        elif version != 2:
+            LOGGER.warning(
+                f"Unknown poetry version {version}, attempting fallback"
+            )
+
+        try:
+            cmd = ["poetry", "show", "--without", "dev"]
+            result = subprocess.run(
+                cmd, capture_output=True, text=True, check=False
+            )
+
+            # If Poetry 2.x throws "Group(s) not found"
+            if "Group(s) not found" in result.stderr:
+                return ["poetry", "show"]
+
+            # Otherwise, if the command succeeded
+            if result.returncode == 0:
+                return cmd
+
+        except FileNotFoundError:
+            return []
+
+        # Default fallback
+        return ["poetry", "show"]
+
     def list_packages(self) -> list[PackageDescription]:
-        cmd = ["poetry", "show", "--no-dev"]
+        version = self._get_poetry_version()
+        cmd = self._generate_list_packages_cmd(version)
         return self._list_packages_from_cmd(cmd)

tests/_runtime/packages/test_package_managers.py

@@ -668,11 +668,14 @@ def test_poetry_list_packages_uses_utf8_encoding(mock_run: MagicMock):
 
     packages = mgr.list_packages()
 
-    # Verify encoding='utf-8' is passed
-    mock_run.assert_called_once()
-    call_kwargs = mock_run.call_args[1]
-    assert call_kwargs.get("encoding") == "utf-8"
-    assert call_kwargs.get("text") is True
+    # Verify encoding='utf-8' is passed (PoetryPackageManager does multiple subprocess calls)
+    encoding_calls = [
+        kwargs
+        for _, kwargs in mock_run.call_args_list
+        if kwargs.get("encoding") == "utf-8"
+    ]
+    assert encoding_calls, "Expected at least one call with encoding='utf-8'"
+    assert all(call.get("text") is True for call in encoding_calls)
 
 
 @pytest.mark.skipif(

tests/_runtime/packages/test_pypi_package_manager.py

@@ -10,6 +10,7 @@
 from marimo._runtime.packages.pypi_package_manager import (
     PackageDescription,
     PipPackageManager,
+    PoetryPackageManager,
     UvPackageManager,
 )
 
@@ -120,6 +121,90 @@ def test_list_packages_failure(mock_run: MagicMock):
     assert len(packages) == 0
 
 
+# Poetry Package Manager Tests
+
+
+def test_poetry_generate_cmd_version_one():
+    mgr = PoetryPackageManager()
+    assert mgr._generate_list_packages_cmd(1) == [
+        "poetry",
+        "show",
+        "--no-dev",
+    ]
+
+
+@patch("subprocess.run")
+def test_poetry_generate_cmd_version_two_prefers_without_dev(
+    mock_run: MagicMock,
+):
+    mock_run.return_value = MagicMock(returncode=0, stderr="")
+    mgr = PoetryPackageManager()
+
+    cmd = mgr._generate_list_packages_cmd(2)
+
+    assert cmd == ["poetry", "show", "--without", "dev"]
+    mock_run.assert_called_once_with(
+        ["poetry", "show", "--without", "dev"],
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+
+
+@patch("subprocess.run")
+def test_poetry_generate_cmd_version_two_falls_back_when_missing_group(
+    mock_run: MagicMock,
+):
+    mock_run.return_value = MagicMock(
+        returncode=1, stderr="Group(s) not found"
+    )
+    mgr = PoetryPackageManager()
+
+    cmd = mgr._generate_list_packages_cmd(2)
+
+    assert cmd == ["poetry", "show"]
+
+
+@patch("subprocess.run")
+def test_poetry_generate_cmd_default_for_other_versions(
+    mock_run: MagicMock,
+):
+    mock_run.return_value = MagicMock(returncode=1, stderr="")
+    mgr = PoetryPackageManager()
+
+    cmd = mgr._generate_list_packages_cmd(3)
+
+    assert cmd == ["poetry", "show"]
+
+
+@patch("subprocess.run")
+def test_poetry_list_packages_parses_output(mock_run: MagicMock):
+    mock_run.side_effect = [
+        MagicMock(returncode=0, stdout="Poetry (1.8.2)"),
+        MagicMock(
+            returncode=0,
+            stdout="package-1    1.0.0\npackage-two    2.0.0\n",
+        ),
+    ]
+    mgr = PoetryPackageManager()
+
+    with patch.object(
+        PoetryPackageManager, "is_manager_installed", return_value=True
+    ):
+        packages = mgr.list_packages()
+
+    assert packages == [
+        PackageDescription(name="package-1", version="1.0.0"),
+        PackageDescription(name="package-two", version="2.0.0"),
+    ]
+
+    # Last subprocess call should be the list invocation with UTF-8 encoding
+    cmd_args, cmd_kwargs = mock_run.call_args_list[-1]
+    assert cmd_args[0] == ["poetry", "show", "--no-dev"]
+    assert cmd_kwargs.get("encoding") == "utf-8"
+    assert cmd_kwargs.get("text") is True
+
+
 # UV Package Manager Tests