pdb: add option to skip `pdb.set_trace()`

changelog/4854.feature.rst

@@ -0,0 +1,5 @@
+The ``--pdb-skip`` option can now be used to ignore calls to
+``pdb.set_trace()`` (and ``pytest.set_trace()``).
+
+This is meant to help while debugging, where you want to use e.g. ``--pdb`` or
+``--trace`` only, or just run the tests again without any interruption.

src/_pytest/debugging.py

@@ -59,6 +59,13 @@ def pytest_addoption(parser):
         action="store_true",
         help="Immediately break when running each test.",
     )
+    group._addoption(
+        "--pdb-skip",
+        "--pdb-ignore-set_trace",
+        dest="pdb_ignore_set_trace",
+        action="store_true",
+        help="Ignore calls to pdb.set_trace().",
+    )
 
 
 def pytest_configure(config):
@@ -202,6 +209,9 @@ class pytestPDB(object):
     @classmethod
     def set_trace(cls, *args, **kwargs):
         """Invoke debugging via ``Pdb.set_trace``, dropping any IO capturing."""
+        if pytestPDB._config:  # Might not be available when called directly.
+            if pytestPDB._config.getoption("pdb_ignore_set_trace"):
+                return
         frame = sys._getframe().f_back
         _pdb = cls._init_pdb(*args, **kwargs)
         _pdb.set_trace(frame)

testing/test_pdb.py

@@ -10,6 +10,7 @@ import sys
 import _pytest._code
 import pytest
 from _pytest.debugging import _validate_usepdb_cls
+from _pytest.main import EXIT_NOTESTSCOLLECTED
 
 try:
     breakpoint
@@ -1112,3 +1113,16 @@ def test_pdb_suspends_fixture_capturing(testdir, fixture):
     assert child.exitstatus == 0
     assert "= 1 passed in " in rest
     assert "> PDB continue (IO-capturing resumed for fixture %s) >" % (fixture) in rest
+
+
+def test_pdb_skip_option(testdir):
+    p = testdir.makepyfile(
+        """
+        print("before_set_trace")
+        __import__('pdb').set_trace()
+        print("after_set_trace")
+        """
+    )
+    result = testdir.runpytest_inprocess("--pdb-ignore-set_trace", "-s", p)
+    assert result.ret == EXIT_NOTESTSCOLLECTED
+    result.stdout.fnmatch_lines(["*before_set_trace*", "*after_set_trace*"])