From a246437d0d48c11c53d0af0c0baf287ff7419350 Mon Sep 17 00:00:00 2001
From: "Nathaniel J. Smith" <njs@pobox.com>
Date: Sun, 24 Dec 2017 19:49:01 -0800
Subject: [PATCH] Remove trio.format_exception

Deprecated in 0.2.0 (see gh-347)
---
 trio/_core/_multierror.py           | 19 +------------------
 trio/_core/tests/test_multierror.py | 13 +------------
 trio/_toplevel_core_reexports.py    |  1 -
 3 files changed, 2 insertions(+), 31 deletions(-)

diff --git a/trio/_core/_multierror.py b/trio/_core/_multierror.py
index 64099d5f25..63a5a5a0d6 100644
--- a/trio/_core/_multierror.py
+++ b/trio/_core/_multierror.py
@@ -7,9 +7,7 @@
 
 import attr
 
-from .._deprecate import deprecated
-
-__all__ = ["MultiError", "format_exception"]
+__all__ = ["MultiError"]
 
 ################################################################
 # MultiError
@@ -349,21 +347,6 @@ def concat_tb(head, tail):
 # MultiErrors
 ################################################################
 
-
-@deprecated("0.2.0", issue=347, instead="traceback.format_exception")
-def format_exception(etype, value, tb, *, limit=None, chain=True):
-    """Like :func:`traceback.format_exception`, but with special support for
-    printing :exc:`MultiError` objects.
-
-    This is a pure, stateless function, and thus safe to call from any
-    thread at any time.
-
-    """
-    return traceback.format_exception(
-        etype, value, tb, limit=limit, chain=chain
-    )
-
-
 traceback_exception_original_init = traceback.TracebackException.__init__
 
 
diff --git a/trio/_core/tests/test_multierror.py b/trio/_core/tests/test_multierror.py
index de3139cbc1..3692abfda0 100644
--- a/trio/_core/tests/test_multierror.py
+++ b/trio/_core/tests/test_multierror.py
@@ -11,9 +11,7 @@
 from .tutil import slow
 
 from ..._deprecate import TrioDeprecationWarning
-from .._multierror import (
-    MultiError, concat_tb, format_exception as trio_format_exception
-)
+from .._multierror import MultiError, concat_tb
 
 
 def raiser1():
@@ -487,15 +485,6 @@ def raise2_raiser1():
         formatted
     )
 
-    # Deprecation
-
-    with pytest.warns(TrioDeprecationWarning) as record:
-        exc_info = einfo(make_tree())
-        assert format_exception(*exc_info) == trio_format_exception(*exc_info)
-
-    assert 'trio.format_exception is deprecated since Trio 0.2.0; ' \
-           'use traceback.format_exception instead' in record[0].message.args[0]
-
 
 def test_logging(caplog):
     exc1 = get_exc(raiser1)
diff --git a/trio/_toplevel_core_reexports.py b/trio/_toplevel_core_reexports.py
index 1d74262f38..27a64e7098 100644
--- a/trio/_toplevel_core_reexports.py
+++ b/trio/_toplevel_core_reexports.py
@@ -21,7 +21,6 @@
     "ResourceBusyError",
     "MultiError",
     "run",
-    "format_exception",
     "open_nursery",
     "open_cancel_scope",
     "current_effective_deadline",