From acbdc5f18fdd86c8bd735dd3eacaa51e988ffdc9 Mon Sep 17 00:00:00 2001
From: Daniel Hahler <git@thequod.de>
Date: Mon, 7 Sep 2020 23:51:45 +0200
Subject: [PATCH 1/2] tests: revisit
 test_pytest_set_trace_used_outside_of_test{,_header}

---
 testing/test_debugging.py | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/testing/test_debugging.py b/testing/test_debugging.py
index e3818a1809a..6efce0d9a01 100644
--- a/testing/test_debugging.py
+++ b/testing/test_debugging.py
@@ -776,19 +776,29 @@ def do_continue(self, arg):
             assert "> PDB continue >" in rest
         assert "= 1 passed in" in rest
 
-    def test_pytest_set_trace_used_outside_of_test(self, testdir):
+    def test_pytest_set_trace_used_outside_of_test(self, testdir: "Testdir") -> None:
         p1 = testdir.makepyfile(
             """
             import pytest
             pytest.set_trace()
             x = 5
-        """
+            pytest.set_trace(header="custom_header")
+            x = 6
+            """
         )
-        child = testdir.spawn("{} {}".format(sys.executable, p1))
-        child.expect("x = 5")
-        child.expect("Pdb")
-        child.sendeof()
-        self.flush(child)
+        result = testdir.run(sys.executable, p1, stdin="c\nc\n")
+        result.stdout.fnmatch_lines(
+            [
+                "> */test_pytest_set_trace_used_outside_of_test.py(3)<module>()",
+                "-> x = 5",
+                "(Pdb) custom_header",
+                "> */test_pytest_set_trace_used_outside_of_test.py(5)<module>()",
+                "-> x = 6",
+                "(Pdb) ",
+            ],
+            complete=True,
+        )
+        assert result.ret == 0
 
     def test_pdb_used_in_generate_tests(self, testdir):
         p1 = testdir.makepyfile(

From 8dedf33fa84a26f32aa9109bd1214d741f7665ff Mon Sep 17 00:00:00 2001
From: Daniel Hahler <git@thequod.de>
Date: Tue, 8 Sep 2020 13:19:31 +0200
Subject: [PATCH 2/2] testing/conftest.py:
 wrap_sys_settrace_for_pdb_with_coverage

---
 testing/conftest.py | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/testing/conftest.py b/testing/conftest.py
index 9a30253079b..9abd1aac788 100644
--- a/testing/conftest.py
+++ b/testing/conftest.py
@@ -9,6 +9,8 @@
 from _pytest.pytester import RunResult
 
 if TYPE_CHECKING:
+    from typing import Generator
+
     from _pytest.config import Config
 
 
@@ -18,7 +20,9 @@ def pytest_addoption(parser):
     )
 
 
-if sys.gettrace():
+orig_trace = sys.gettrace()
+
+if orig_trace:
 
     @pytest.fixture(autouse=True)
     def restore_tracing():
@@ -26,11 +30,26 @@ def restore_tracing():
 
         https://bugs.python.org/issue37011
         """
-        orig_trace = sys.gettrace()
+        assert orig_trace == sys.gettrace(), (orig_trace, sys.gettrace())
         yield
         if sys.gettrace() != orig_trace:
             sys.settrace(orig_trace)
 
+    orig_settrace = sys.settrace
+
+    def wrapped_settrace(tracer):
+        if tracer is None:
+            orig_settrace(orig_trace)
+        else:
+            orig_settrace(tracer)
+
+    @pytest.fixture(autouse=True)
+    def wrap_sys_settrace_for_pdb_with_coverage(
+        monkeypatch,
+    ) -> "Generator[None, None, None]":
+        monkeypatch.setattr("sys.settrace", wrapped_settrace)
+        yield
+
 
 @pytest.hookimpl
 def pytest_runtest_setup(item):