Fix environment regression

docs/changelog/3099.bugfix.rst

@@ -0,0 +1 @@
+Fix regression introduced in ``4.9.0`` affecting hyphenated and combined environments.

src/tox/session/env_select.py

@@ -4,7 +4,7 @@
 import re
 from collections import Counter
 from dataclasses import dataclass
-from itertools import chain
+from itertools import chain, permutations
 from typing import TYPE_CHECKING, Dict, Iterable, Iterator, List, cast
 
 from tox.config.loader.str_convert import StrConvert
@@ -155,10 +155,12 @@ def _collect_names(self) -> Iterator[tuple[Iterable[str], bool]]:
             cli_envs_not_in_config = set(self._cli_envs) - set(self._state.conf)
             if cli_envs_not_in_config:
                 # allow cli_envs matching ".pkg" and starting with "py" to be implicitly created.
-                disallowed_cli_envs = [
-                    env for env in cli_envs_not_in_config if not env.startswith("py") and env not in (".pkg",)
-                ]
-                if disallowed_cli_envs:
+                disallowed_cli_envs = [env for env in cli_envs_not_in_config if not _is_valid_exception(env)]
+
+                # allow disallowed cli envs that match hyphenated combinations
+                has_match = any(_find_env_match(cli_env, set(self._state.conf)) for cli_env in disallowed_cli_envs)
+
+                if disallowed_cli_envs and not has_match:
                     msg = f"provided environments not found in configuration file: {disallowed_cli_envs}"
                     raise HandledError(msg)
             yield self._cli_envs, True
@@ -389,6 +391,16 @@ def _mark_provision(self, on: bool, provision_tox_env: str) -> None:  # noqa: FB
         self._provision = on, provision_tox_env
 
 
+def _find_env_match(value: str, state_conf: set[str]) -> bool:
+    return any(value in conf.split("-") for conf in state_conf) or any(
+        value == "-".join(combo) for combo in permutations(state_conf, 2)
+    )
+
+
+def _is_valid_exception(env: str) -> bool:
+    return env.startswith("py") or env in (".pkg",)
+
+
 __all__ = [
     "register_env_select_flags",
     "EnvSelector",

tests/session/test_env_select.py

@@ -164,3 +164,40 @@ def test_allowed_implicit_cli_envs(env_name: str, tox_project: ToxProjectCreator
     outcome.assert_success()
     assert env_name in outcome.out
     assert not outcome.err
+
+
+@pytest.mark.parametrize("env_name", ["a", "b", "a-b"])
+def test_matches_hyphenated_env(env_name: str, tox_project: ToxProjectCreator) -> None:
+    tox_ini = """
+        [tox]
+        env_list=a-b
+        [testenv]
+        package=skip
+        commands_pre =
+            a: python -c 'print("a")'
+            b: python -c 'print("b")'
+        commands=python -c 'print("ok")'
+    """
+    proj = tox_project({"tox.ini": tox_ini})
+    outcome = proj.run("r", "-e", env_name)
+    outcome.assert_success()
+    assert env_name in outcome.out
+    assert not outcome.err
+
+
+@pytest.mark.parametrize("env_name", ["3.9", "3.9-cov"])
+def test_matches_combined_env(env_name: str, tox_project: ToxProjectCreator) -> None:
+    tox_ini = """
+        [tox]
+        env_list=3.9
+        [testenv]
+        package=skip
+        commands =
+            !cov: python -c 'print("without cov")'
+            cov: python -c 'print("with cov")'
+    """
+    proj = tox_project({"tox.ini": tox_ini})
+    outcome = proj.run("r", "-e", env_name)
+    outcome.assert_success()
+    assert env_name in outcome.out
+    assert not outcome.err