diff --git a/libcxx/utils/libcxx/test/config.py b/libcxx/utils/libcxx/test/config.py
--- a/libcxx/utils/libcxx/test/config.py
+++ b/libcxx/utils/libcxx/test/config.py
@@ -624,6 +624,11 @@
             '--codesign_identity "{}"'.format(codesign_ident),
             '--env {}'.format(env_vars)
         ]
+        # The exec_nowrapper substitution is used for configuration checks.
+        sub.append(('%{exec_nowrapper}', '{} {} -- '.format(self.executor, ' '.join(exec_args))))
+        if self.lit_config.run_with_debugger:
+            exec_args.append("--wrapper-command")
+            exec_args.append(pipes.quote(' '.join(map(pipes.quote, self.lit_config.debugger_args))))
         sub.append(('%{exec}', '{} {} -- '.format(self.executor, ' '.join(exec_args))))
         if self.get_lit_conf('libcxx_gdb'):
             sub.append(('%{libcxx_gdb}', self.get_lit_conf('libcxx_gdb')))
diff --git a/libcxx/utils/libcxx/test/dsl.py b/libcxx/utils/libcxx/test/dsl.py
--- a/libcxx/utils/libcxx/test/dsl.py
+++ b/libcxx/utils/libcxx/test/dsl.py
@@ -109,8 +109,10 @@
       if exitCode != 0:
         return None
 
+      # Note: We use exec_nowrapper here to avoid running the configuration
+      # tests under GDB/valgrind/etc.
       out, err, exitCode, _ = _executeScriptInternal(test, [
-        "%{{exec}} %t.exe {}".format(' '.join(args))
+        "%{{exec_nowrapper}} %t.exe {}".format(' '.join(args))
       ])
       if exitCode != 0:
         return None
diff --git a/llvm/utils/lit/lit/LitConfig.py b/llvm/utils/lit/lit/LitConfig.py
--- a/llvm/utils/lit/lit/LitConfig.py
+++ b/llvm/utils/lit/lit/LitConfig.py
@@ -1,14 +1,15 @@
 from __future__ import absolute_import
+
 import inspect
 import os
-import platform
 import sys
 
 import lit.Test
-import lit.formats
 import lit.TestingConfig
+import lit.formats
 import lit.util
 
+
 # LitConfig must be a new style class for properties to work
 class LitConfig(object):
     """LitConfig - Configuration data for a 'lit' test runner instance, shared
@@ -26,6 +27,7 @@
                  params, config_prefix = None,
                  maxIndividualTestTime = 0,
                  parallelism_groups = {},
+                 run_with_debugger = None,
                  echo_all_commands = False):
         # The name of the test runner.
         self.progname = progname
@@ -63,6 +65,17 @@
                 self.valgrindArgs.append('--leak-check=no')
             self.valgrindArgs.extend(self.valgrindUserArgs)
 
+        self.run_with_debugger = run_with_debugger is not None
+        self.debugger_args = []
+        if self.run_with_debugger:
+            if run_with_debugger == 'gdb':
+                # We use "thread apply all bt" instead of "bt" to ensure that a
+                # successful exit doesn't cause GDB to return a non-zero exit code
+                # due the program no longer existing when "bt" is executed.
+                self.debugger_args = ["gdb", "--quiet", "--batch", "--return-child-result",
+                                      "-ex=r", "-ex=thread apply all bt", "--args"]
+            else:
+                raise ValueError("Unsupported debugger: " + run_with_debugger)
         self.maxIndividualTestTime = maxIndividualTestTime
         self.parallelism_groups = parallelism_groups
         self.echo_all_commands = echo_all_commands
diff --git a/llvm/utils/lit/lit/cl_arguments.py b/llvm/utils/lit/lit/cl_arguments.py
--- a/llvm/utils/lit/lit/cl_arguments.py
+++ b/llvm/utils/lit/lit/cl_arguments.py
@@ -171,6 +171,15 @@
     debug_group.add_argument("--show-used-features",
             help="Show all features used in the test suite (in XFAIL, UNSUPPORTED and REQUIRES) and exit",
             action="store_true")
+    # TODO: Also support lldb
+    debug_group.add_argument("--run-with-debugger",
+             help="Run tests with gdb and print a backtrace on crash. "
+                  "This is currently only supported for libc++/libunwind.",
+             choices=("gdb", ))
+    debug_group.add_argument("--gdb",
+             dest="run_with_debugger",
+             help="This is an alias for --run-with-debugger=gdb.",
+             action="store_const", const="gdb")
 
     # LIT is special: environment variables override command line arguments.
     env_args = shlex.split(os.environ.get("LIT_OPTS", ""))
diff --git a/llvm/utils/lit/lit/main.py b/llvm/utils/lit/lit/main.py
--- a/llvm/utils/lit/lit/main.py
+++ b/llvm/utils/lit/lit/main.py
@@ -37,6 +37,7 @@
         isWindows=is_windows,
         params=params,
         config_prefix=opts.configPrefix,
+        run_with_debugger=opts.run_with_debugger,
         echo_all_commands=opts.echoAllCommands)
 
     discovered_tests = lit.discovery.find_tests_for_inputs(lit_config, opts.test_paths)