Create a .gitignore in work_dir and info file directories

Closes tox-dev#2530

src/tox/session/env_select.py

@@ -413,6 +413,9 @@ def iter( # noqa: A003
  yield name
 
  def ensure_only_run_env_is_active(self) -> None:
+ if not self._state.conf.core["work_dir"].exists():
+ self._state.conf.core["work_dir"].mkdir()
+ (self._state.conf.core["work_dir"] / ".gitignore").write_text("*", encoding="utf-8")
  envs, active = self._defined_envs, self._env_name_to_active()
  invalid = [n for n, a in active.items() if a and isinstance(envs[n].env, PackageToxEnv)]
  if invalid:

src/tox/tox_env/info.py

@@ -63,6 +63,8 @@ def reset(self) -> None:
 
  def _write(self) -> None:
  self._path.parent.mkdir(parents=True, exist_ok=True)
+ if not (self._path.parent / ".gitignore").exists():
+ (self._path.parent / ".gitignore").write_text("*", encoding="utf-8")
  self._path.write_text(json.dumps(self._content, indent=2))