Fix devenv when package for env is wheel/editable (#2820)

Resolves #2815

Author: gaborbernat

docs/changelog/2815.bugfix.rst

@@ -0,0 +1 @@
+``devenv`` does not respect the specified path when the package is a wheel file - by :user:`gaborbernat`.

src/tox/config/main.py

@@ -7,6 +7,7 @@
 
 from tox.config.loader.api import Loader, OverrideMap
 
+from .loader.memory import MemoryLoader
 from .loader.section import Section
 from .sets import ConfigSet, CoreConfigSet, EnvConfigSet
 from .source import Source
@@ -41,6 +42,7 @@ def __init__(
         self._src = config_source
         self._key_to_conf_set: dict[tuple[str, str], ConfigSet] = OrderedDict()
         self._core_set: CoreConfigSet | None = None
+        self.memory_seed_loaders: defaultdict[str, list[MemoryLoader]] = defaultdict(list)
 
     def pos_args(self, to_path: Path | None) -> tuple[str, ...] | None:
         """
@@ -132,6 +134,8 @@ def get_section_config(
         except KeyError:
             conf_set = of_type(self, section, for_env)
             self._key_to_conf_set[key] = conf_set
+            if for_env is not None:
+                conf_set.loaders.extend(self.memory_seed_loaders.get(for_env, []))
             for loader in self._src.get_loaders(section, base, self._overrides, conf_set):
                 conf_set.loaders.append(loader)
             if loaders is not None:

src/tox/session/cmd/devenv.py

@@ -17,31 +17,31 @@
 def tox_add_option(parser: ToxParser) -> None:
     help_msg = "sets up a development environment at ENVDIR based on the tox configuration specified "
     our = parser.add_command("devenv", ["d"], help_msg, devenv)
-    our.add_argument("devenv_path", metavar="path", default=Path("venv").absolute(), nargs="?")
+    our.add_argument("devenv_path", metavar="path", default=Path("venv"), nargs="?", type=Path)
     register_env_select_flags(our, default=CliEnv("py"), multiple=False)
     env_run_create_flags(our, mode="devenv")
 
 
 def devenv(state: State) -> int:
     opt = state.conf.options
+    opt.devenv_path = opt.devenv_path.absolute()
     opt.skip_missing_interpreters = False  # the target python must exist
     opt.no_test = False  # do not run the test suite
     opt.package_only = False
     opt.install_pkg = None  # no explicit packages to install
     opt.skip_pkg_install = False  # always install a package in this case
     opt.no_test = True  # do not run the test phase
+    loader = MemoryLoader(  # these configuration values are loaded from in-memory always (no file conf)
+        usedevelop=True,  # dev environments must be of type dev
+        env_dir=opt.devenv_path,  # move it in source
+    )
+    state.conf.memory_seed_loaders[list(opt.env)[0]].append(loader)
 
     state.envs.ensure_only_run_env_is_active()
     envs = list(state.envs.iter())
     if len(envs) != 1:
         raise HandledError(f"exactly one target environment allowed in devenv mode but found {', '.join(envs)}")
-    loader = MemoryLoader(  # these configuration values are loaded from in-memory always (no file conf)
-        usedevelop=True,  # dev environments must be of type dev
-        env_dir=Path(opt.devenv_path),  # move it in source
-    )
-    tox_env = state.envs[envs[0]]
-    tox_env.conf.loaders.insert(0, loader)
     result = run_sequential(state)
     if result == 0:
-        logging.warning(f"created development environment under {tox_env.conf['env_dir']}")
+        logging.warning(f"created development environment under {opt.devenv_path}")
     return result

tests/session/cmd/test_devenv.py

@@ -6,15 +6,18 @@
 
 
 def test_devenv_fail_multiple_target(tox_project: ToxProjectCreator) -> None:
-    outcome = tox_project({"tox.ini": ""}).run("d", "-e", "py39,py38")
+    outcome = tox_project({"tox.ini": ""}).run("d", "-e", "a,b")
     outcome.assert_failed()
-    msg = "ROOT: HandledError| exactly one target environment allowed in devenv mode but found py39, py38\n"
+    msg = "ROOT: HandledError| exactly one target environment allowed in devenv mode but found a, b\n"
     outcome.assert_out_err(msg, "")
 
 
 @pytest.mark.integration()
 def test_devenv_ok(tox_project: ToxProjectCreator, enable_pip_pypi_access: str | None) -> None:  # noqa: U100
-    content = {"setup.py": "from setuptools import setup\nsetup(name='demo', version='1.0')"}
+    content = {
+        "setup.py": "from setuptools import setup\nsetup(name='demo', version='1.0')",
+        "tox.ini": "[tox]\nenv_list = py\n[testenv]\nusedevelop = True",
+    }
     project = tox_project(content)
     outcome = project.run("d", "-e", "py")