diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index f75ac6ba..078703be 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
 -   repo: https://github.com/PyCQA/autoflake
-    rev: v2.2.0
+    rev: v2.2.1
     hooks:
     -   id: autoflake
         name: autoflake
@@ -8,7 +8,7 @@ repos:
         language: python
         files: \.py$
 -   repo: https://github.com/asottile/reorder-python-imports
-    rev: v3.10.0
+    rev: v3.12.0
     hooks:
     -   id: reorder-python-imports
         args: ['--application-directories=.:src', --py38-plus]
@@ -24,12 +24,12 @@ repos:
     hooks:
     -   id: rst-backticks
 -   repo: https://github.com/asottile/pyupgrade
-    rev: v3.10.1
+    rev: v3.15.0
     hooks:
     -   id: pyupgrade
         args: [--py38-plus]
 -   repo: https://github.com/psf/black
-    rev: 23.7.0
+    rev: 23.12.1
     hooks:
     -   id: black
         args: [--safe, --quiet]
@@ -47,7 +47,7 @@ repos:
         language: python
         additional_dependencies: [pygments, restructuredtext_lint]
 -   repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v1.5.1
+    rev: v1.8.0
     hooks:
     -   id: mypy
         files: ^(src/|testing/)
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 2ce57326..d7af1746 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -21,6 +21,25 @@ Versions follow `Semantic Versioning <https://semver.org/>`_ (``<major>.<minor>.
 
 .. towncrier release notes start
 
+pluggy 1.4.0 (2024-01-24)
+=========================
+
+Features
+--------
+
+- `#463 <https://github.com/pytest-dev/pluggy/issues/463>`_: A warning :class:`~pluggy.PluggyTeardownRaisedWarning` is now issued when an old-style hookwrapper raises an exception during teardown.
+  See the warning documentation for more details.
+
+- `#471 <https://github.com/pytest-dev/pluggy/issues/471>`_: Add :func:`PluginManager.unblock <pluggy.PluginManager.unblock>` method to unblock a plugin by plugin name.
+
+Bug Fixes
+---------
+
+- `#441 <https://github.com/pytest-dev/pluggy/issues/441>`_: Fix :func:`~pluggy.HookCaller.call_extra()` extra methods getting ordered before everything else in some circumstances. Regressed in pluggy 1.1.0.
+
+- `#438 <https://github.com/pytest-dev/pluggy/issues/438>`_: Fix plugins registering other plugins in a hook when the other plugins implement the same hook itself. Regressed in pluggy 1.1.0.
+
+
 pluggy 1.3.0 (2023-08-26)
 =========================
 
@@ -148,7 +167,7 @@ Features
 --------
 
 - `#282 <https://github.com/pytest-dev/pluggy/issues/282>`_: When registering a hookimpl which is declared as ``hookwrapper=True`` but whose
-  function is not a generator function, a ``PluggyValidationError`` exception is
+  function is not a generator function, a :class:`~pluggy.PluginValidationError` exception is
   now raised.
 
   Previously this problem would cause an error only later, when calling the hook.
@@ -158,7 +177,7 @@ Features
 
   .. code-block:: python
 
-      def my_hook_real_implementation(arg):
+      def my_hook_implementation(arg):
           print("before")
           yield
           print("after")
diff --git a/docs/api_reference.rst b/docs/api_reference.rst
index 40b27bfe..b14d725d 100644
--- a/docs/api_reference.rst
+++ b/docs/api_reference.rst
@@ -47,3 +47,15 @@ API Reference
 .. autoclass:: pluggy.HookimplOpts()
     :show-inheritance:
     :members:
+
+
+Warnings
+--------
+
+Custom warnings generated in some situations such as improper usage or deprecated features.
+
+.. autoclass:: pluggy.PluggyWarning()
+    :show-inheritance:
+
+.. autoclass:: pluggy.PluggyTeardownRaisedWarning()
+    :show-inheritance:
diff --git a/docs/conf.py b/docs/conf.py
index ece874a2..aaa6c966 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -45,7 +45,7 @@
     "github_button": "true",
     "github_banner": "true",
     "github_type": "star",
-    "badge_branch": "master",
+    "badge_branch": "main",
     "page_width": "1080px",
     "sidebar_width": "300px",
     "fixed_sidebar": "false",
diff --git a/docs/index.rst b/docs/index.rst
index d527a507..42fb8f49 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -416,9 +416,11 @@ of the hook thus far, or, if the previous calls raised an exception, it is
 :py:meth:`thrown <python:generator.throw>` the exception.
 
 The function should do one of two things:
-- Return a value, which can be the same value as received from the ``yield``, or
-something else entirely.
+
+- Return a value, which can be the same value as received from the ``yield``, or something else entirely.
+
 - Raise an exception.
+
 The return value or exception propagate to further hook wrappers, and finally
 to the hook caller.
 
@@ -1028,11 +1030,11 @@ Table of contents
 .. _callbacks:
     https://en.wikipedia.org/wiki/Callback_(computer_programming)
 .. _tox test suite:
-    https://github.com/pytest-dev/pluggy/blob/master/tox.ini
+    https://github.com/pytest-dev/pluggy/blob/main/tox.ini
 .. _Semantic Versioning:
     https://semver.org/
 .. _Python interpreters:
-    https://github.com/pytest-dev/pluggy/blob/master/tox.ini#L2
+    https://github.com/pytest-dev/pluggy/blob/main/tox.ini#L2
 .. _500+ plugins:
     https://docs.pytest.org/en/latest/reference/plugin_list.html
 .. _pre-commit:
diff --git a/src/pluggy/__init__.py b/src/pluggy/__init__.py
index 9d9e873b..2adf9454 100644
--- a/src/pluggy/__init__.py
+++ b/src/pluggy/__init__.py
@@ -18,6 +18,8 @@
     "HookspecMarker",
     "HookimplMarker",
     "Result",
+    "PluggyWarning",
+    "PluggyTeardownRaisedWarning",
 ]
 
 from ._manager import PluginManager, PluginValidationError
@@ -31,3 +33,7 @@
     HookimplOpts,
     HookImpl,
 )
+from ._warnings import (
+    PluggyWarning,
+    PluggyTeardownRaisedWarning,
+)
diff --git a/src/pluggy/_callers.py b/src/pluggy/_callers.py
index 6498eaed..787f56ba 100644
--- a/src/pluggy/_callers.py
+++ b/src/pluggy/_callers.py
@@ -3,27 +3,52 @@
 """
 from __future__ import annotations
 
+import warnings
 from typing import cast
 from typing import Generator
 from typing import Mapping
+from typing import NoReturn
 from typing import Sequence
 from typing import Tuple
 from typing import Union
 
 from ._hooks import HookImpl
-from ._result import _raise_wrapfail
 from ._result import HookCallError
 from ._result import Result
+from ._warnings import PluggyTeardownRaisedWarning
 
 
 # Need to distinguish between old- and new-style hook wrappers.
-# Wrapping one a singleton tuple is the fastest type-safe way I found to do it.
+# Wrapping with a tuple is the fastest type-safe way I found to do it.
 Teardown = Union[
-    Tuple[Generator[None, Result[object], None]],
+    Tuple[Generator[None, Result[object], None], HookImpl],
     Generator[None, object, object],
 ]
 
 
+def _raise_wrapfail(
+    wrap_controller: (
+        Generator[None, Result[object], None] | Generator[None, object, object]
+    ),
+    msg: str,
+) -> NoReturn:
+    co = wrap_controller.gi_code
+    raise RuntimeError(
+        "wrap_controller at %r %s:%d %s"
+        % (co.co_name, co.co_filename, co.co_firstlineno, msg)
+    )
+
+
+def _warn_teardown_exception(
+    hook_name: str, hook_impl: HookImpl, e: BaseException
+) -> None:
+    msg = "A plugin raised an exception during an old-style hookwrapper teardown.\n"
+    msg += f"Plugin: {hook_impl.plugin_name}, Hook: {hook_name}\n"
+    msg += f"{type(e).__name__}: {e}\n"
+    msg += "For more information see https://pluggy.readthedocs.io/en/stable/api_reference.html#pluggy.PluggyTeardownRaisedWarning"  # noqa: E501
+    warnings.warn(PluggyTeardownRaisedWarning(msg), stacklevel=5)
+
+
 def _multicall(
     hook_name: str,
     hook_impls: Sequence[HookImpl],
@@ -60,7 +85,7 @@ def _multicall(
                         res = hook_impl.function(*args)
                         wrapper_gen = cast(Generator[None, Result[object], None], res)
                         next(wrapper_gen)  # first yield
-                        teardowns.append((wrapper_gen,))
+                        teardowns.append((wrapper_gen, hook_impl))
                     except StopIteration:
                         _raise_wrapfail(wrapper_gen, "did not yield")
                 elif hook_impl.wrapper:
@@ -128,9 +153,13 @@ def _multicall(
                 if isinstance(teardown, tuple):
                     try:
                         teardown[0].send(outcome)
-                        _raise_wrapfail(teardown[0], "has second yield")
                     except StopIteration:
                         pass
+                    except BaseException as e:
+                        _warn_teardown_exception(hook_name, teardown[1], e)
+                        raise
+                    else:
+                        _raise_wrapfail(teardown[0], "has second yield")
                 else:
                     try:
                         if outcome._exception is not None:
diff --git a/src/pluggy/_hooks.py b/src/pluggy/_hooks.py
index 916ca704..7c8420f4 100644
--- a/src/pluggy/_hooks.py
+++ b/src/pluggy/_hooks.py
@@ -389,6 +389,13 @@ def __init__(
         #: Name of the hook getting called.
         self.name: Final = name
         self._hookexec: Final = hook_execute
+        # The hookimpls list. The caller iterates it *in reverse*. Format:
+        # 1. trylast nonwrappers
+        # 2. nonwrappers
+        # 3. tryfirst nonwrappers
+        # 4. trylast wrappers
+        # 5. wrappers
+        # 6. tryfirst wrappers
         self._hookimpls: Final[list[HookImpl]] = []
         self._call_history: _CallHistory | None = None
         # TODO: Document, or make private.
@@ -490,7 +497,8 @@ def __call__(self, **kwargs: object) -> Any:
         ), "Cannot directly call a historic hook - use call_historic instead."
         self._verify_all_args_are_provided(kwargs)
         firstresult = self.spec.opts.get("firstresult", False) if self.spec else False
-        return self._hookexec(self.name, self._hookimpls, kwargs, firstresult)
+        # Copy because plugins may register other plugins during iteration (#438).
+        return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
 
     def call_historic(
         self,
@@ -511,7 +519,8 @@ def call_historic(
         self._call_history.append((kwargs, result_callback))
         # Historizing hooks don't return results.
         # Remember firstresult isn't compatible with historic.
-        res = self._hookexec(self.name, self._hookimpls, kwargs, False)
+        # Copy because plugins may register other plugins during iteration (#438).
+        res = self._hookexec(self.name, self._hookimpls.copy(), kwargs, False)
         if result_callback is None:
             return
         if isinstance(res, list):
@@ -541,10 +550,11 @@ def call_extra(
             hookimpl = HookImpl(None, "<temp>", method, opts)
             # Find last non-tryfirst nonwrapper method.
             i = len(hookimpls) - 1
-            while (
-                i >= 0
-                and hookimpls[i].tryfirst
-                and not (hookimpls[i].hookwrapper or hookimpls[i].wrapper)
+            while i >= 0 and (
+                # Skip wrappers.
+                (hookimpls[i].hookwrapper or hookimpls[i].wrapper)
+                # Skip tryfirst nonwrappers.
+                or hookimpls[i].tryfirst
             ):
                 i -= 1
             hookimpls.insert(i + 1, hookimpl)
diff --git a/src/pluggy/_manager.py b/src/pluggy/_manager.py
index 84717e6e..ce1e107a 100644
--- a/src/pluggy/_manager.py
+++ b/src/pluggy/_manager.py
@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-import importlib.metadata
 import inspect
 import types
 import warnings
@@ -11,6 +10,7 @@
 from typing import Iterable
 from typing import Mapping
 from typing import Sequence
+from typing import TYPE_CHECKING
 
 from . import _tracing
 from ._callers import _multicall
@@ -26,6 +26,10 @@
 from ._hooks import normalize_hookimpl_opts
 from ._result import Result
 
+if TYPE_CHECKING:
+    # importtlib.metadata import is slow, defer it.
+    import importlib.metadata
+
 
 _BeforeTrace = Callable[[str, Sequence[HookImpl], Mapping[str, Any]], None]
 _AfterTrace = Callable[[Result[Any], str, Sequence[HookImpl], Mapping[str, Any]], None]
@@ -231,6 +235,16 @@ def is_blocked(self, name: str) -> bool:
         """Return whether the given plugin name is blocked."""
         return name in self._name2plugin and self._name2plugin[name] is None
 
+    def unblock(self, name: str) -> bool:
+        """Unblocks a name.
+
+        Returns whether the name was actually blocked.
+        """
+        if self._name2plugin.get(name, -1) is None:
+            del self._name2plugin[name]
+            return True
+        return False
+
     def add_hookspecs(self, module_or_class: _Namespace) -> None:
         """Add new hook specifications defined in the given ``module_or_class``.
 
@@ -384,6 +398,8 @@ def load_setuptools_entrypoints(self, group: str, name: str | None = None) -> in
         :return:
             The number of plugins loaded by this call.
         """
+        import importlib.metadata
+
         count = 0
         for dist in list(importlib.metadata.distributions()):
             for ep in dist.entry_points:
diff --git a/src/pluggy/_result.py b/src/pluggy/_result.py
index 29859eb9..aa21fa13 100644
--- a/src/pluggy/_result.py
+++ b/src/pluggy/_result.py
@@ -7,9 +7,7 @@
 from typing import Callable
 from typing import cast
 from typing import final
-from typing import Generator
 from typing import Generic
-from typing import NoReturn
 from typing import Optional
 from typing import Tuple
 from typing import Type
@@ -20,19 +18,6 @@
 ResultType = TypeVar("ResultType")
 
 
-def _raise_wrapfail(
-    wrap_controller: (
-        Generator[None, Result[ResultType], None] | Generator[None, object, object]
-    ),
-    msg: str,
-) -> NoReturn:
-    co = wrap_controller.gi_code
-    raise RuntimeError(
-        "wrap_controller at %r %s:%d %s"
-        % (co.co_name, co.co_filename, co.co_firstlineno, msg)
-    )
-
-
 class HookCallError(Exception):
     """Hook was called incorrectly."""
 
diff --git a/src/pluggy/_warnings.py b/src/pluggy/_warnings.py
new file mode 100644
index 00000000..6356c770
--- /dev/null
+++ b/src/pluggy/_warnings.py
@@ -0,0 +1,27 @@
+from typing import final
+
+
+class PluggyWarning(UserWarning):
+    """Base class for all warnings emitted by pluggy."""
+
+    __module__ = "pluggy"
+
+
+@final
+class PluggyTeardownRaisedWarning(PluggyWarning):
+    """A plugin raised an exception during an :ref:`old-style hookwrapper
+    <old_style_hookwrappers>` teardown.
+
+    Such exceptions are not handled by pluggy, and may cause subsequent
+    teardowns to be executed at unexpected times, or be skipped entirely.
+
+    This is an issue in the plugin implementation.
+
+    If the exception is unintended, fix the underlying cause.
+
+    If the exception is intended, switch to :ref:`new-style hook wrappers
+    <hookwrappers>`, or use :func:`result.force_exception()
+    <pluggy.Result.force_exception>` to set the exception instead of raising.
+    """
+
+    __module__ = "pluggy"
diff --git a/testing/test_hookcaller.py b/testing/test_hookcaller.py
index 88ed1316..9eb6f979 100644
--- a/testing/test_hookcaller.py
+++ b/testing/test_hookcaller.py
@@ -1,4 +1,5 @@
 from typing import Callable
+from typing import Generator
 from typing import List
 from typing import Sequence
 from typing import TypeVar
@@ -448,3 +449,74 @@ def conflict(self) -> None:
         "Hook 'conflict' is already registered within namespace "
         "<class 'test_hookcaller.test_hook_conflict.<locals>.Api1'>"
     )
+
+
+def test_call_extra_hook_order(hc: HookCaller, addmeth: AddMeth) -> None:
+    """Ensure that call_extra is calling hooks in the right order."""
+    order = []
+
+    @addmeth(tryfirst=True)
+    def method1() -> str:
+        order.append("1")
+        return "1"
+
+    @addmeth()
+    def method2() -> str:
+        order.append("2")
+        return "2"
+
+    @addmeth(trylast=True)
+    def method3() -> str:
+        order.append("3")
+        return "3"
+
+    @addmeth(wrapper=True, tryfirst=True)
+    def method4() -> Generator[None, str, str]:
+        order.append("4pre")
+        result = yield
+        order.append("4post")
+        return result
+
+    @addmeth(wrapper=True)
+    def method5() -> Generator[None, str, str]:
+        order.append("5pre")
+        result = yield
+        order.append("5post")
+        return result
+
+    @addmeth(wrapper=True, trylast=True)
+    def method6() -> Generator[None, str, str]:
+        order.append("6pre")
+        result = yield
+        order.append("6post")
+        return result
+
+    def extra1() -> str:
+        order.append("extra1")
+        return "extra1"
+
+    def extra2() -> str:
+        order.append("extra2")
+        return "extra2"
+
+    result = hc.call_extra([extra1, extra2], {"arg": "test"})
+    assert order == [
+        "4pre",
+        "5pre",
+        "6pre",
+        "1",
+        "extra2",
+        "extra1",
+        "2",
+        "3",
+        "6post",
+        "5post",
+        "4post",
+    ]
+    assert result == [
+        "1",
+        "extra2",
+        "extra1",
+        "2",
+        "3",
+    ]
diff --git a/testing/test_pluginmanager.py b/testing/test_pluginmanager.py
index 81b86b65..d3bcac4e 100644
--- a/testing/test_pluginmanager.py
+++ b/testing/test_pluginmanager.py
@@ -110,6 +110,13 @@ class A:
     pm.unregister(name="somename")
     assert pm.is_blocked("somename")
 
+    # Unblock.
+    assert not pm.unblock("someothername")
+    assert pm.unblock("somename")
+    assert not pm.is_blocked("somename")
+    assert not pm.unblock("somename")
+    assert pm.register(A(), "somename")
+
 
 def test_register_mismatch_method(he_pm: PluginManager) -> None:
     class hello:
@@ -675,3 +682,79 @@ def he_method1(self):
         assert saveindent[0] > indent
     finally:
         undo()
+
+
+@pytest.mark.parametrize("historic", [False, True])
+def test_register_while_calling(
+    pm: PluginManager,
+    historic: bool,
+) -> None:
+    """Test that registering an impl of a hook while it is being called does
+    not affect the call itself, only later calls.
+
+    For historic hooks however, the hook is called immediately on registration.
+
+    Regression test for #438.
+    """
+    hookspec = HookspecMarker("example")
+
+    class Hooks:
+        @hookspec(historic=historic)
+        def configure(self) -> int:
+            raise NotImplementedError()
+
+    class Plugin1:
+        @hookimpl
+        def configure(self) -> int:
+            return 1
+
+    class Plugin2:
+        def __init__(self) -> None:
+            self.already_registered = False
+
+        @hookimpl
+        def configure(self) -> int:
+            if not self.already_registered:
+                pm.register(Plugin4())
+                pm.register(Plugin5())
+                pm.register(Plugin6())
+                self.already_registered = True
+            return 2
+
+    class Plugin3:
+        @hookimpl
+        def configure(self) -> int:
+            return 3
+
+    class Plugin4:
+        @hookimpl(tryfirst=True)
+        def configure(self) -> int:
+            return 4
+
+    class Plugin5:
+        @hookimpl()
+        def configure(self) -> int:
+            return 5
+
+    class Plugin6:
+        @hookimpl(trylast=True)
+        def configure(self) -> int:
+            return 6
+
+    pm.add_hookspecs(Hooks)
+    pm.register(Plugin1())
+    pm.register(Plugin2())
+    pm.register(Plugin3())
+
+    if not historic:
+        result = pm.hook.configure()
+        assert result == [3, 2, 1]
+        result = pm.hook.configure()
+        assert result == [4, 5, 3, 2, 1, 6]
+    else:
+        result = []
+        pm.hook.configure.call_historic(result.append)
+        assert result == [4, 5, 6, 3, 2, 1]
+        result = []
+        pm.hook.configure.call_historic(result.append)
+        assert result == [4, 5, 3, 2, 1, 6]
diff --git a/testing/test_warnings.py b/testing/test_warnings.py
new file mode 100644
index 00000000..4f5454be
--- /dev/null
+++ b/testing/test_warnings.py
@@ -0,0 +1,49 @@
+from pathlib import Path
+
+import pytest
+
+from pluggy import HookimplMarker
+from pluggy import HookspecMarker
+from pluggy import PluggyTeardownRaisedWarning
+from pluggy import PluginManager
+
+
+hookspec = HookspecMarker("example")
+hookimpl = HookimplMarker("example")
+
+
+def test_teardown_raised_warning(pm: PluginManager) -> None:
+    class Api:
+        @hookspec
+        def my_hook(self):
+            raise NotImplementedError()
+
+    pm.add_hookspecs(Api)
+
+    class Plugin1:
+        @hookimpl
+        def my_hook(self):
+            pass
+
+    class Plugin2:
+        @hookimpl(hookwrapper=True)
+        def my_hook(self):
+            yield
+            1 / 0
+
+    class Plugin3:
+        @hookimpl(hookwrapper=True)
+        def my_hook(self):
+            yield
+
+    pm.register(Plugin1(), "plugin1")
+    pm.register(Plugin2(), "plugin2")
+    pm.register(Plugin3(), "plugin3")
+    with pytest.warns(
+        PluggyTeardownRaisedWarning,
+        match=r"\bplugin2\b.*\bmy_hook\b.*\n.*ZeroDivisionError",
+    ) as wc:
+        with pytest.raises(ZeroDivisionError):
+            pm.hook.my_hook()
+    assert len(wc.list) == 1
+    assert Path(wc.list[0].filename).name == "test_warnings.py"