diff --git a/src/_pytest/assertion/rewrite.py b/src/_pytest/assertion/rewrite.py
index cec0c5501..e77b1b0b8 100644
--- a/src/_pytest/assertion/rewrite.py
+++ b/src/_pytest/assertion/rewrite.py
@@ -23,6 +23,8 @@ from typing import Set
 from typing import Tuple
 from typing import Union
 
+import py
+
 from _pytest._io.saferepr import saferepr
 from _pytest._version import version
 from _pytest.assertion import util
@@ -177,10 +179,10 @@ class AssertionRewritingHook(importlib.abc.MetaPathFinder, importlib.abc.Loader)
         """
         if self.session is not None and not self._session_paths_checked:
             self._session_paths_checked = True
-            for path in self.session._initialpaths:
+            for initial_path in self.session._initialpaths:
                 # Make something as c:/projects/my_project/path.py ->
                 #     ['c:', 'projects', 'my_project', 'path.py']
-                parts = str(path).split(os.path.sep)
+                parts = str(initial_path).split(os.path.sep)
                 # add 'path' to basenames to be checked.
                 self._basenames_to_check_rewrite.add(os.path.splitext(parts[-1])[0])
 
@@ -213,7 +215,7 @@ class AssertionRewritingHook(importlib.abc.MetaPathFinder, importlib.abc.Loader)
             return True
 
         if self.session is not None:
-            if self.session.isinitpath(fn):
+            if self.session.isinitpath(py.path.local(fn)):
                 state.trace(
                     "matched test file (was specified on cmdline): {!r}".format(fn)
                 )
diff --git a/src/_pytest/cacheprovider.py b/src/_pytest/cacheprovider.py
index 305a122e9..967272ca6 100755
--- a/src/_pytest/cacheprovider.py
+++ b/src/_pytest/cacheprovider.py
@@ -495,7 +495,7 @@ def pytest_report_header(config: Config) -> Optional[str]:
         # starting with .., ../.. if sensible
 
         try:
-            displaypath = cachedir.relative_to(config.rootdir)
+            displaypath = cachedir.relative_to(str(config.rootdir))
         except ValueError:
             displaypath = cachedir
         return "cachedir: {}".format(displaypath)
diff --git a/src/_pytest/config/__init__.py b/src/_pytest/config/__init__.py
index 2ae9ac849..e154f162b 100644
--- a/src/_pytest/config/__init__.py
+++ b/src/_pytest/config/__init__.py
@@ -308,10 +308,9 @@ class PytestPluginManager(PluginManager):
         self._dirpath2confmods = {}  # type: Dict[Any, List[object]]
         # Maps a py.path.local to a module object.
         self._conftestpath2mod = {}  # type: Dict[Any, object]
-        self._confcutdir = None
+        self._confcutdir = None  # type: Optional[py.path.local]
         self._noconftest = False
-        # Set of py.path.local's.
-        self._duplicatepaths = set()  # type: Set[Any]
+        self._duplicatepaths = set()  # type: Set[py.path.local]
 
         self.add_hookspecs(_pytest.hookspec)
         self.register(self)
@@ -945,13 +944,12 @@ class Config:
         ns, unknown_args = self._parser.parse_known_and_unknown_args(
             args, namespace=copy.copy(self.option)
         )
-        r = determine_setup(
+        self.rootdir, self.inifile, self.inicfg = determine_setup(
             ns.inifilename,
             ns.file_or_dir + unknown_args,
             rootdir_cmd_arg=ns.rootdir or None,
             config=self,
         )
-        self.rootdir, self.inifile, self.inicfg = r
         self._parser.extra_info["rootdir"] = self.rootdir
         self._parser.extra_info["inifile"] = self.inifile
         self._parser.addini("addopts", "extra command line options", "args")
@@ -1162,6 +1160,8 @@ class Config:
         #   in this case, we already have a list ready to use
         #
         if type == "pathlist":
+            # TODO: This assert is probably not valid in all cases.
+            assert self.inifile is not None
             dp = py.path.local(self.inifile).dirpath()
             input_values = shlex.split(value) if isinstance(value, str) else value
             return [dp.join(x, abs=True) for x in input_values]
diff --git a/src/_pytest/config/findpaths.py b/src/_pytest/config/findpaths.py
index 796fa9b0a..ae8c5f47f 100644
--- a/src/_pytest/config/findpaths.py
+++ b/src/_pytest/config/findpaths.py
@@ -63,7 +63,7 @@ def load_config_dict_from_file(
     elif filepath.ext == ".toml":
         import toml
 
-        config = toml.load(filepath)
+        config = toml.load(str(filepath))
 
         result = config.get("tool", {}).get("pytest", {}).get("ini_options", None)
         if result is not None:
@@ -161,16 +161,18 @@ def determine_setup(
     args: List[str],
     rootdir_cmd_arg: Optional[str] = None,
     config: Optional["Config"] = None,
-) -> Tuple[py.path.local, Optional[str], Dict[str, Union[str, List[str]]]]:
+) -> Tuple[py.path.local, Optional[py.path.local], Dict[str, Union[str, List[str]]]]:
     rootdir = None
     dirs = get_dirs_from_args(args)
     if inifile:
-        inicfg = load_config_dict_from_file(py.path.local(inifile)) or {}
+        inipath_ = py.path.local(inifile)
+        inipath = inipath_  # type: Optional[py.path.local]
+        inicfg = load_config_dict_from_file(inipath_) or {}
         if rootdir_cmd_arg is None:
             rootdir = get_common_ancestor(dirs)
     else:
         ancestor = get_common_ancestor(dirs)
-        rootdir, inifile, inicfg = locate_config([ancestor])
+        rootdir, inipath, inicfg = locate_config([ancestor])
         if rootdir is None and rootdir_cmd_arg is None:
             for possible_rootdir in ancestor.parts(reverse=True):
                 if possible_rootdir.join("setup.py").exists():
@@ -178,7 +180,7 @@ def determine_setup(
                     break
             else:
                 if dirs != [ancestor]:
-                    rootdir, inifile, inicfg = locate_config(dirs)
+                    rootdir, inipath, inicfg = locate_config(dirs)
                 if rootdir is None:
                     if config is not None:
                         cwd = config.invocation_dir
@@ -196,4 +198,5 @@ def determine_setup(
                     rootdir
                 )
             )
-    return rootdir, inifile, inicfg or {}
+    assert rootdir is not None
+    return rootdir, inipath, inicfg or {}
diff --git a/src/_pytest/logging.py b/src/_pytest/logging.py
index ef90c94e8..04bf74b6c 100644
--- a/src/_pytest/logging.py
+++ b/src/_pytest/logging.py
@@ -586,7 +586,7 @@ class LoggingPlugin:
         fpath = Path(fname)
 
         if not fpath.is_absolute():
-            fpath = Path(self._config.rootdir, fpath)
+            fpath = Path(str(self._config.rootdir), fpath)
 
         if not fpath.parent.exists():
             fpath.parent.mkdir(exist_ok=True, parents=True)
diff --git a/src/_pytest/main.py b/src/_pytest/main.py
index a95f2f2e7..096df12dc 100644
--- a/src/_pytest/main.py
+++ b/src/_pytest/main.py
@@ -439,7 +439,7 @@ class Session(nodes.FSCollector):
         )  # type: Dict[Tuple[Type[nodes.Collector], str], CollectReport]
 
         # Dirnames of pkgs with dunder-init files.
-        self._collection_pkg_roots = {}  # type: Dict[py.path.local, Package]
+        self._collection_pkg_roots = {}  # type: Dict[str, Package]
 
         self._bestrelpathcache = _bestrelpath_cache(
             config.rootdir
@@ -601,7 +601,7 @@ class Session(nodes.FSCollector):
                             col = self._collectfile(pkginit, handle_dupes=False)
                             if col:
                                 if isinstance(col[0], Package):
-                                    self._collection_pkg_roots[parent] = col[0]
+                                    self._collection_pkg_roots[str(parent)] = col[0]
                                 # always store a list in the cache, matchnodes expects it
                                 self._collection_node_cache1[col[0].fspath] = [col[0]]
 
@@ -623,8 +623,8 @@ class Session(nodes.FSCollector):
                         for x in self._collectfile(pkginit):
                             yield x
                             if isinstance(x, Package):
-                                self._collection_pkg_roots[dirpath] = x
-                if dirpath in self._collection_pkg_roots:
+                                self._collection_pkg_roots[str(dirpath)] = x
+                if str(dirpath) in self._collection_pkg_roots:
                     # Do not collect packages here.
                     continue
 
diff --git a/src/_pytest/nodes.py b/src/_pytest/nodes.py
index 3757e0b27..c6c77f529 100644
--- a/src/_pytest/nodes.py
+++ b/src/_pytest/nodes.py
@@ -393,7 +393,7 @@ class Node(metaclass=NodeMeta):
         # It will be better to just always display paths relative to invocation_dir, but
         # this requires a lot of plumbing (#6428).
         try:
-            abspath = Path(os.getcwd()) != Path(self.config.invocation_dir)
+            abspath = Path(os.getcwd()) != Path(str(self.config.invocation_dir))
         except OSError:
             abspath = True
 
diff --git a/src/_pytest/python.py b/src/_pytest/python.py
index 4b716c616..c52771057 100644
--- a/src/_pytest/python.py
+++ b/src/_pytest/python.py
@@ -656,7 +656,7 @@ class Package(Module):
 
             parts_ = parts(path.strpath)
             if any(
-                pkg_prefix in parts_ and pkg_prefix.join("__init__.py") != path
+                str(pkg_prefix) in parts_ and pkg_prefix.join("__init__.py") != path
                 for pkg_prefix in pkg_prefixes
             ):
                 continue
@@ -1332,7 +1332,7 @@ def _show_fixtures_per_test(config, session):
 
     def get_best_relpath(func):
         loc = getlocation(func, curdir)
-        return curdir.bestrelpath(loc)
+        return curdir.bestrelpath(py.path.local(loc))
 
     def write_fixture(fixture_def):
         argname = fixture_def.argname
@@ -1406,7 +1406,7 @@ def _showfixtures_main(config: Config, session: Session) -> None:
                 (
                     len(fixturedef.baseid),
                     fixturedef.func.__module__,
-                    curdir.bestrelpath(loc),
+                    curdir.bestrelpath(py.path.local(loc)),
                     fixturedef.argname,
                     fixturedef,
                 )
diff --git a/src/_pytest/terminal.py b/src/_pytest/terminal.py
index e89776109..8c2a30739 100644
--- a/src/_pytest/terminal.py
+++ b/src/_pytest/terminal.py
@@ -380,9 +380,9 @@ class TerminalReporter:
             if self.currentfspath is not None and self._show_progress_info:
                 self._write_progress_information_filling_space()
             self.currentfspath = fspath
-            fspath = self.startdir.bestrelpath(fspath)
+            relfspath = self.startdir.bestrelpath(fspath)
             self._tw.line()
-            self._tw.write(fspath + " ")
+            self._tw.write(relfspath + " ")
         self._tw.write(res, flush=True, **markup)
 
     def write_ensure_prefix(self, prefix, extra: str = "", **kwargs) -> None:
diff --git a/testing/acceptance_test.py b/testing/acceptance_test.py
index 7dfd588a0..686fe1b98 100644
--- a/testing/acceptance_test.py
+++ b/testing/acceptance_test.py
@@ -580,8 +580,9 @@ class TestInvocationVariants:
         assert res.ret == 0
         res.stdout.fnmatch_lines(["*1 passed*"])
 
-    def test_equivalence_pytest_pytest(self):
-        assert pytest.main == py.test.cmdline.main
+    def test_equivalence_pytest_pydottest(self) -> None:
+        # Type ignored because `py.test` is not and will not be typed.
+        assert pytest.main == py.test.cmdline.main  # type: ignore[attr-defined]
 
     def test_invoke_with_invalid_type(self):
         with pytest.raises(
diff --git a/testing/test_config.py b/testing/test_config.py
index 31dfd9fa3..fc128dd25 100644
--- a/testing/test_config.py
+++ b/testing/test_config.py
@@ -629,13 +629,14 @@ class TestConfigFromdictargs:
         )
         with cwd.ensure(dir=True).as_cwd():
             config = Config.fromdictargs(option_dict, ())
+            inipath = py.path.local(inifile)
 
         assert config.args == [str(cwd)]
         assert config.option.inifilename == inifile
         assert config.option.capture == "no"
 
         # this indicates this is the file used for getting configuration values
-        assert config.inifile == inifile
+        assert config.inifile == inipath
         assert config.inicfg.get("name") == "value"
         assert config.inicfg.get("should_not_be_set") is None