Don't break into `pdb` for `raise unittest.SkipTest()`

src/_pytest/debugging.py

@@ -3,6 +3,7 @@ import argparse
 import functools
 import sys
 import types
+import unittest
 from typing import Any
 from typing import Callable
 from typing import Generator
@@ -293,6 +294,8 @@ class PdbInvoke:
             sys.stdout.write(out)
             sys.stdout.write(err)
         assert call.excinfo is not None
+
+        if not isinstance(call.excinfo.value, unittest.SkipTest):
             _enter_pdb(node, call.excinfo, report)
 
     def pytest_internalerror(self, excinfo: ExceptionInfo[BaseException]) -> None:

testing/test_debugging.py

@@ -124,6 +124,18 @@ class TestPDB:
         assert rep.skipped
         assert len(pdblist) == 0
         
+    def test_pdb_on_raise_skiptest(self, pytester, pdblist) -> None:
+        rep = runpdb_and_get_report(
+            pytester,
+            """
+            import unittest
+            
+            raise unittest.SkipTest("This is a common way to skip an entire file.")
+        """,
+        )
+        assert rep.skipped
+        assert len(pdblist) == 0
+
     def test_pdb_on_BdbQuit(self, pytester, pdblist) -> None:
         rep = runpdb_and_get_report(
             pytester,