Remove special handling due to IPython lacking support for exception groups

newsfragments/2702.removal.rst

@@ -0,0 +1 @@
+Removed special ``MultiError`` traceback handling for IPython. As of `version 8.15 <https://ipython.readthedocs.io/en/stable/whatsnew/version8.html#ipython-8-15>`_ `ExceptionGroup` is handled natively.

test-requirements.in

@@ -3,7 +3,6 @@ pytest >= 5.0         # for faulthandler in core
 coverage >= 7.2.5
 async_generator >= 1.9
 pyright
-ipython               # for the IPython traceback integration tests
 pyOpenSSL >= 22.0.0   # for the ssl + DTLS tests
 trustme               # for the ssl + DTLS tests
 pylint                # for pylint finding all symbols tests

test-requirements.txt

@@ -8,16 +8,12 @@ astor==0.8.1
     # via -r test-requirements.in
 astroid==2.15.6
     # via pylint
-asttokens==2.2.1
-    # via stack-data
 async-generator==1.10
     # via -r test-requirements.in
 attrs==23.1.0
     # via
     #   -r test-requirements.in
     #   outcome
-backcall==0.2.0
-    # via ipython
 black==23.7.0 ; implementation_name == "cpython"
     # via -r test-requirements.in
 build==0.10.0
@@ -38,16 +34,12 @@ cryptography==41.0.3
     #   pyopenssl
     #   trustme
     #   types-pyopenssl
-decorator==5.1.1
-    # via ipython
 dill==0.3.7
     # via pylint
 exceptiongroup==1.1.3 ; python_version < "3.11"
     # via
     #   -r test-requirements.in
     #   pytest
-executing==1.2.0
-    # via stack-data
 flake8==6.1.0
     # via
     #   -r test-requirements.in
@@ -60,18 +52,12 @@ idna==3.4
     #   trustme
 iniconfig==2.0.0
     # via pytest
-ipython==8.12.2
-    # via -r test-requirements.in
 isort==5.12.0
     # via pylint
 jedi==0.19.0
-    # via
-    #   -r test-requirements.in
-    #   ipython
+    # via -r test-requirements.in
 lazy-object-proxy==1.9.0
     # via astroid
-matplotlib-inline==0.1.6
-    # via ipython
 mccabe==0.7.0
     # via
     #   flake8
@@ -96,10 +82,6 @@ parso==0.8.3
     # via jedi
 pathspec==0.11.2
     # via black
-pexpect==4.8.0
-    # via ipython
-pickleshare==0.7.5
-    # via ipython
 pip-tools==7.3.0
     # via -r test-requirements.in
 platformdirs==3.10.0
@@ -108,20 +90,12 @@ platformdirs==3.10.0
     #   pylint
 pluggy==1.3.0
     # via pytest
-prompt-toolkit==3.0.39
-    # via ipython
-ptyprocess==0.7.0
-    # via pexpect
-pure-eval==0.2.2
-    # via stack-data
 pycodestyle==2.11.0
     # via flake8
 pycparser==2.21
     # via cffi
 pyflakes==3.1.0
     # via flake8
-pygments==2.16.1
-    # via ipython
 pylint==2.17.5
     # via -r test-requirements.in
 pyopenssl==23.2.0
@@ -132,14 +106,10 @@ pyright==1.1.325
     # via -r test-requirements.in
 pytest==7.4.0
     # via -r test-requirements.in
-six==1.16.0
-    # via asttokens
 sniffio==1.3.0
     # via -r test-requirements.in
 sortedcontainers==2.4.0
     # via -r test-requirements.in
-stack-data==0.6.2
-    # via ipython
 tomli==2.0.1
     # via
     #   black
@@ -152,10 +122,6 @@ tomli==2.0.1
     #   pytest
 tomlkit==0.12.1
     # via pylint
-traitlets==5.9.0
-    # via
-    #   ipython
-    #   matplotlib-inline
 trustme==1.1.0
     # via -r test-requirements.in
 types-pyopenssl==23.2.0.2 ; implementation_name == "cpython"
@@ -165,11 +131,8 @@ typing-extensions==4.7.1
     #   -r test-requirements.in
     #   astroid
     #   black
-    #   ipython
     #   mypy
     #   pylint
-wcwidth==0.2.6
-    # via prompt-toolkit
 wheel==0.41.2
     # via pip-tools
 wrapt==1.15.0

trio/_core/_multierror.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import sys
-import warnings
 from collections.abc import Callable, Sequence
 from types import TracebackType
 from typing import TYPE_CHECKING, Any, cast, overload
@@ -11,9 +10,7 @@
 from trio._deprecate import warn_deprecated
 
 if sys.version_info < (3, 11):
-    from exceptiongroup import BaseExceptionGroup, ExceptionGroup, print_exception
-else:
-    from traceback import print_exception
+    from exceptiongroup import BaseExceptionGroup, ExceptionGroup
 
 if TYPE_CHECKING:
     from typing_extensions import Self
@@ -461,37 +458,6 @@ def concat_tb(
     return current_head
 
 
-# Remove when IPython gains support for exception groups
-# (https://github.com/ipython/ipython/issues/13753)
-if "IPython" in sys.modules:
-    import IPython
-
-    ip = IPython.get_ipython()
-    if ip is not None:
-        if ip.custom_exceptions != ():
-            warnings.warn(
-                "IPython detected, but you already have a custom exception "
-                "handler installed. I'll skip installing Trio's custom "
-                "handler, but this means exception groups will not show full "
-                "tracebacks.",
-                category=RuntimeWarning,
-            )
-        else:
-
-            def trio_show_traceback(
-                self: IPython.core.interactiveshell.InteractiveShell,
-                etype: type[BaseException],
-                value: BaseException,
-                tb: TracebackType,
-                tb_offset: int | None = None,
-            ) -> None:
-                # XX it would be better to integrate with IPython's fancy
-                # exception formatting stuff (and not ignore tb_offset)
-                print_exception(value)
-
-            ip.set_custom_exc((BaseExceptionGroup,), trio_show_traceback)
-
-
 # Ubuntu's system Python has a sitecustomize.py file that import
 # apport_python_hook and replaces sys.excepthook.
 #

trio/_core/_tests/test_multierror.py

@@ -430,7 +430,7 @@ def test_non_base_multierror():
     assert isinstance(exc, ExceptionGroup)
 
 
-def run_script(name, use_ipython=False):
+def run_script(name: str) -> subprocess.CompletedProcess[bytes]:
     import trio
 
     trio_path = Path(trio.__file__).parent.parent
@@ -447,24 +447,7 @@ def run_script(name, use_ipython=False):
     env["PYTHONPATH"] = os.pathsep.join(pp)
     print("subprocess PYTHONPATH:", env.get("PYTHONPATH"))
 
-    if use_ipython:
-        lines = [
-            "import runpy",
-            f"runpy.run_path(r'{script_path}', run_name='trio.fake')",
-            "exit()",
-        ]
-
-        cmd = [
-            sys.executable,
-            "-u",
-            "-m",
-            "IPython",
-            # no startup files
-            "--quick",
-            "--TerminalIPythonApp.code_to_run=" + "\n".join(lines),
-        ]
-    else:
-        cmd = [sys.executable, "-u", str(script_path)]
+    cmd = [sys.executable, "-u", str(script_path)]
     print("running:", cmd)
     completed = subprocess.run(
         cmd, env=env, stdout=subprocess.PIPE, stderr=subprocess.STDOUT
@@ -474,69 +457,6 @@ def run_script(name, use_ipython=False):
     return completed
 
 
-def check_simple_excepthook(completed):
-    assert_match_in_seq(
-        [
-            "in <module>",
-            "MultiError",
-            "--- 1 ---",
-            "in exc1_fn",
-            "ValueError",
-            "--- 2 ---",
-            "in exc2_fn",
-            "KeyError",
-        ],
-        completed.stdout.decode("utf-8"),
-    )
-
-
-try:
-    import IPython  # noqa: F401
-except ImportError:  # pragma: no cover
-    have_ipython = False
-else:
-    have_ipython = True
-
-need_ipython = pytest.mark.skipif(not have_ipython, reason="need IPython")
-
-
-@slow
-@need_ipython
-def test_ipython_exc_handler():
-    completed = run_script("simple_excepthook.py", use_ipython=True)
-    check_simple_excepthook(completed)
-
-
-@slow
-@need_ipython
-def test_ipython_imported_but_unused():
-    completed = run_script("simple_excepthook_IPython.py")
-    check_simple_excepthook(completed)
-
-
-@slow
-@need_ipython
-def test_ipython_custom_exc_handler():
-    # Check we get a nice warning (but only one!) if the user is using IPython
-    # and already has some other set_custom_exc handler installed.
-    completed = run_script("ipython_custom_exc.py", use_ipython=True)
-    assert_match_in_seq(
-        [
-            # The warning
-            "RuntimeWarning",
-            "IPython detected",
-            "skip installing Trio",
-            # The MultiError
-            "MultiError",
-            "ValueError",
-            "KeyError",
-        ],
-        completed.stdout.decode("utf-8"),
-    )
-    # Make sure our other warning doesn't show up
-    assert "custom sys.excepthook" not in completed.stdout.decode("utf-8")
-
-
 @slow
 @pytest.mark.skipif(
     not Path("/usr/lib/python3/dist-packages/apport_python_hook.py").exists(),