diff --git a/Lib/test/test_faulthandler.py b/Lib/test/test_faulthandler.py
new file mode 100644
index 000000000..5e73f7381
--- /dev/null
+++ b/Lib/test/test_faulthandler.py
@@ -0,0 +1,974 @@
+from contextlib import contextmanager
+import datetime
+import faulthandler
+import os
+import re
+import signal
+import subprocess
+import sys
+from test import support
+from test.support import os_helper
+from test.support import script_helper, is_android
+from test.support import skip_if_sanitizer
+import tempfile
+import unittest
+from textwrap import dedent
+
+try:
+    import _testcapi
+except ImportError:
+    _testcapi = None
+
+TIMEOUT = 0.5
+MS_WINDOWS = (os.name == 'nt')
+
+
+def expected_traceback(lineno1, lineno2, header, min_count=1):
+    regex = header
+    regex += '  File "<string>", line %s in func\n' % lineno1
+    regex += '  File "<string>", line %s in <module>' % lineno2
+    if 1 < min_count:
+        return '^' + (regex + '\n') * (min_count - 1) + regex
+    else:
+        return '^' + regex + '$'
+
+def skip_segfault_on_android(test):
+    # Issue #32138: Raising SIGSEGV on Android may not cause a crash.
+    return unittest.skipIf(is_android,
+                           'raising SIGSEGV on Android is unreliable')(test)
+
+@contextmanager
+def temporary_filename():
+    filename = tempfile.mktemp()
+    try:
+        yield filename
+    finally:
+        os_helper.unlink(filename)
+
+class FaultHandlerTests(unittest.TestCase):
+    def get_output(self, code, filename=None, fd=None):
+        """
+        Run the specified code in Python (in a new child process) and read the
+        output from the standard error or from a file (if filename is set).
+        Return the output lines as a list.
+
+        Strip the reference count from the standard error for Python debug
+        build, and replace "Current thread 0x00007f8d8fbd9700" by "Current
+        thread XXX".
+        """
+        code = dedent(code).strip()
+        pass_fds = []
+        if fd is not None:
+            pass_fds.append(fd)
+        with support.SuppressCrashReport():
+            process = script_helper.spawn_python('-c', code, pass_fds=pass_fds)
+            with process:
+                output, stderr = process.communicate()
+                exitcode = process.wait()
+        output = output.decode('ascii', 'backslashreplace')
+        if filename:
+            self.assertEqual(output, '')
+            with open(filename, "rb") as fp:
+                output = fp.read()
+            output = output.decode('ascii', 'backslashreplace')
+        elif fd is not None:
+            self.assertEqual(output, '')
+            os.lseek(fd, os.SEEK_SET, 0)
+            with open(fd, "rb", closefd=False) as fp:
+                output = fp.read()
+            output = output.decode('ascii', 'backslashreplace')
+        return output.splitlines(), exitcode
+
+    def check_error(self, code, lineno, fatal_error, *,
+                    filename=None, all_threads=True, other_regex=None,
+                    fd=None, know_current_thread=True,
+                    py_fatal_error=False,
+                    garbage_collecting=False,
+                    function='<module>'):
+        """
+        Check that the fault handler for fatal errors is enabled and check the
+        traceback from the child process output.
+
+        Raise an error if the output doesn't match the expected format.
+        """
+        if all_threads:
+            if know_current_thread:
+                header = 'Current thread 0x[0-9a-f]+'
+            else:
+                header = 'Thread 0x[0-9a-f]+'
+        else:
+            header = 'Stack'
+        regex = [f'^{fatal_error}']
+        if py_fatal_error:
+            regex.append("Python runtime state: initialized")
+        regex.append('')
+        regex.append(fr'{header} \(most recent call first\):')
+        if garbage_collecting:
+            regex.append('  Garbage-collecting')
+        regex.append(fr'  File "<string>", line {lineno} in {function}')
+        regex = '\n'.join(regex)
+
+        if other_regex:
+            regex = f'(?:{regex}|{other_regex})'
+
+        # Enable MULTILINE flag
+        regex = f'(?m){regex}'
+        output, exitcode = self.get_output(code, filename=filename, fd=fd)
+        output = '\n'.join(output)
+        self.assertRegex(output, regex)
+        self.assertNotEqual(exitcode, 0)
+
+    def check_fatal_error(self, code, line_number, name_regex, func=None, **kw):
+        if func:
+            name_regex = '%s: %s' % (func, name_regex)
+        fatal_error = 'Fatal Python error: %s' % name_regex
+        self.check_error(code, line_number, fatal_error, **kw)
+
+    def check_windows_exception(self, code, line_number, name_regex, **kw):
+        fatal_error = 'Windows fatal exception: %s' % name_regex
+        self.check_error(code, line_number, fatal_error, **kw)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @unittest.skipIf(sys.platform.startswith('aix'),
+                     "the first page of memory is a mapped read-only on AIX")
+    def test_read_null(self):
+        if not MS_WINDOWS:
+            self.check_fatal_error("""
+                import faulthandler
+                faulthandler.enable()
+                faulthandler._read_null()
+                """,
+                3,
+                # Issue #12700: Read NULL raises SIGILL on Mac OS X Lion
+                '(?:Segmentation fault'
+                    '|Bus error'
+                    '|Illegal instruction)')
+        else:
+            self.check_windows_exception("""
+                import faulthandler
+                faulthandler.enable()
+                faulthandler._read_null()
+                """,
+                3,
+                'access violation')
+
+    # TODO: RUSTPYTHON, AssertionError: Regex didn't match
+    @unittest.expectedFailure
+    @skip_segfault_on_android
+    def test_sigsegv(self):
+        self.check_fatal_error("""
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._sigsegv()
+            """,
+            3,
+            'Segmentation fault')
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @skip_segfault_on_android
+    def test_gc(self):
+        # bpo-44466: Detect if the GC is running
+        self.check_fatal_error("""
+            import faulthandler
+            import gc
+            import sys
+
+            faulthandler.enable()
+
+            class RefCycle:
+                def __del__(self):
+                    faulthandler._sigsegv()
+
+            # create a reference cycle which triggers a fatal
+            # error in a destructor
+            a = RefCycle()
+            b = RefCycle()
+            a.b = b
+            b.a = a
+
+            # Delete the objects, not the cycle
+            a = None
+            b = None
+
+            # Break the reference cycle: call __del__()
+            gc.collect()
+
+            # Should not reach this line
+            print("exit", file=sys.stderr)
+            """,
+            9,
+            'Segmentation fault',
+            function='__del__',
+            garbage_collecting=True)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_fatal_error_c_thread(self):
+        self.check_fatal_error("""
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._fatal_error_c_thread()
+            """,
+            3,
+            'in new thread',
+            know_current_thread=False,
+            func='faulthandler_fatal_error_thread',
+            py_fatal_error=True)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_sigabrt(self):
+        self.check_fatal_error("""
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._sigabrt()
+            """,
+            3,
+            'Aborted')
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @unittest.skipIf(sys.platform == 'win32',
+                     "SIGFPE cannot be caught on Windows")
+    def test_sigfpe(self):
+        self.check_fatal_error("""
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._sigfpe()
+            """,
+            3,
+            'Floating point exception')
+
+    @unittest.skipIf(_testcapi is None, 'need _testcapi')
+    @unittest.skipUnless(hasattr(signal, 'SIGBUS'), 'need signal.SIGBUS')
+    @skip_segfault_on_android
+    def test_sigbus(self):
+        self.check_fatal_error("""
+            import faulthandler
+            import signal
+
+            faulthandler.enable()
+            signal.raise_signal(signal.SIGBUS)
+            """,
+            5,
+            'Bus error')
+
+    @unittest.skipIf(_testcapi is None, 'need _testcapi')
+    @unittest.skipUnless(hasattr(signal, 'SIGILL'), 'need signal.SIGILL')
+    @skip_segfault_on_android
+    def test_sigill(self):
+        self.check_fatal_error("""
+            import faulthandler
+            import signal
+
+            faulthandler.enable()
+            signal.raise_signal(signal.SIGILL)
+            """,
+            5,
+            'Illegal instruction')
+
+    def check_fatal_error_func(self, release_gil):
+        # Test that Py_FatalError() dumps a traceback
+        with support.SuppressCrashReport():
+            self.check_fatal_error(f"""
+                import _testcapi
+                _testcapi.fatal_error(b'xyz', {release_gil})
+                """,
+                2,
+                'xyz',
+                func='test_fatal_error',
+                py_fatal_error=True)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_fatal_error(self):
+        self.check_fatal_error_func(False)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_fatal_error_without_gil(self):
+        self.check_fatal_error_func(True)
+
+    @unittest.skipIf(sys.platform.startswith('openbsd'),
+                     "Issue #12868: sigaltstack() doesn't work on "
+                     "OpenBSD if Python is compiled with pthread")
+    @unittest.skipIf(not hasattr(faulthandler, '_stack_overflow'),
+                     'need faulthandler._stack_overflow()')
+    def test_stack_overflow(self):
+        self.check_fatal_error("""
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._stack_overflow()
+            """,
+            3,
+            '(?:Segmentation fault|Bus error)',
+            other_regex='unable to raise a stack overflow')
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @skip_segfault_on_android
+    def test_gil_released(self):
+        self.check_fatal_error("""
+            import faulthandler
+            faulthandler.enable()
+            faulthandler._sigsegv(True)
+            """,
+            3,
+            'Segmentation fault')
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @skip_if_sanitizer(memory=True, ub=True, reason="sanitizer "
+                       "builds change crashing process output.")
+    @skip_segfault_on_android
+    def test_enable_file(self):
+        with temporary_filename() as filename:
+            self.check_fatal_error("""
+                import faulthandler
+                output = open({filename}, 'wb')
+                faulthandler.enable(output)
+                faulthandler._sigsegv()
+                """.format(filename=repr(filename)),
+                4,
+                'Segmentation fault',
+                filename=filename)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @unittest.skipIf(sys.platform == "win32",
+                     "subprocess doesn't support pass_fds on Windows")
+    @skip_if_sanitizer(memory=True, ub=True, reason="sanitizer "
+                       "builds change crashing process output.")
+    @skip_segfault_on_android
+    def test_enable_fd(self):
+        with tempfile.TemporaryFile('wb+') as fp:
+            fd = fp.fileno()
+            self.check_fatal_error("""
+                import faulthandler
+                import sys
+                faulthandler.enable(%s)
+                faulthandler._sigsegv()
+                """ % fd,
+                4,
+                'Segmentation fault',
+                fd=fd)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @skip_segfault_on_android
+    def test_enable_single_thread(self):
+        self.check_fatal_error("""
+            import faulthandler
+            faulthandler.enable(all_threads=False)
+            faulthandler._sigsegv()
+            """,
+            3,
+            'Segmentation fault',
+            all_threads=False)
+
+    @skip_segfault_on_android
+    def test_disable(self):
+        code = """
+            import faulthandler
+            faulthandler.enable()
+            faulthandler.disable()
+            faulthandler._sigsegv()
+            """
+        not_expected = 'Fatal Python error'
+        stderr, exitcode = self.get_output(code)
+        stderr = '\n'.join(stderr)
+        self.assertTrue(not_expected not in stderr,
+                     "%r is present in %r" % (not_expected, stderr))
+        self.assertNotEqual(exitcode, 0)
+
+    if sys.platform == "win32":  # TODO: RUSTPYTHON, AttributeError: module 'msvcrt' has no attribute 'GetErrorMode'
+        test_disable = unittest.expectedFailure(test_disable)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @skip_segfault_on_android
+    def test_dump_ext_modules(self):
+        code = """
+            import faulthandler
+            import sys
+            # Don't filter stdlib module names
+            sys.stdlib_module_names = frozenset()
+            faulthandler.enable()
+            faulthandler._sigsegv()
+            """
+        stderr, exitcode = self.get_output(code)
+        stderr = '\n'.join(stderr)
+        match = re.search(r'^Extension modules:(.*) \(total: [0-9]+\)$',
+                          stderr, re.MULTILINE)
+        if not match:
+            self.fail(f"Cannot find 'Extension modules:' in {stderr!r}")
+        modules = set(match.group(1).strip().split(', '))
+        for name in ('sys', 'faulthandler'):
+            self.assertIn(name, modules)
+
+    # TODO: RUSTPYTHON, AttributeError: module 'faulthandler' has no attribute 'is_enabled'
+    @unittest.expectedFailure
+    def test_is_enabled(self):
+        orig_stderr = sys.stderr
+        try:
+            # regrtest may replace sys.stderr by io.StringIO object, but
+            # faulthandler.enable() requires that sys.stderr has a fileno()
+            # method
+            sys.stderr = sys.__stderr__
+
+            was_enabled = faulthandler.is_enabled()
+            try:
+                faulthandler.enable()
+                self.assertTrue(faulthandler.is_enabled())
+                faulthandler.disable()
+                self.assertFalse(faulthandler.is_enabled())
+            finally:
+                if was_enabled:
+                    faulthandler.enable()
+                else:
+                    faulthandler.disable()
+        finally:
+            sys.stderr = orig_stderr
+
+    # TODO: RUSTPYTHON, subprocess.CalledProcessError: Command ... returned non-zero exit status 1.
+    @unittest.expectedFailure
+    def test_disabled_by_default(self):
+        # By default, the module should be disabled
+        code = "import faulthandler; print(faulthandler.is_enabled())"
+        args = (sys.executable, "-E", "-c", code)
+        # don't use assert_python_ok() because it always enables faulthandler
+        output = subprocess.check_output(args)
+        self.assertEqual(output.rstrip(), b"False")
+
+    # TODO: RUSTPYTHON, subprocess.CalledProcessError: Command '<filter object at ...>' returned non-zero exit status 1.
+    @unittest.expectedFailure
+    def test_sys_xoptions(self):
+        # Test python -X faulthandler
+        code = "import faulthandler; print(faulthandler.is_enabled())"
+        args = filter(None, (sys.executable,
+                             "-E" if sys.flags.ignore_environment else "",
+                             "-X", "faulthandler", "-c", code))
+        env = os.environ.copy()
+        env.pop("PYTHONFAULTHANDLER", None)
+        # don't use assert_python_ok() because it always enables faulthandler
+        output = subprocess.check_output(args, env=env)
+        self.assertEqual(output.rstrip(), b"True")
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_env_var(self):
+        # empty env var
+        code = "import faulthandler; print(faulthandler.is_enabled())"
+        args = (sys.executable, "-c", code)
+        env = dict(os.environ)
+        env['PYTHONFAULTHANDLER'] = ''
+        env['PYTHONDEVMODE'] = ''
+        # don't use assert_python_ok() because it always enables faulthandler
+        output = subprocess.check_output(args, env=env)
+        self.assertEqual(output.rstrip(), b"False")
+
+        # non-empty env var
+        env = dict(os.environ)
+        env['PYTHONFAULTHANDLER'] = '1'
+        env['PYTHONDEVMODE'] = ''
+        output = subprocess.check_output(args, env=env)
+        self.assertEqual(output.rstrip(), b"True")
+
+    def check_dump_traceback(self, *, filename=None, fd=None):
+        """
+        Explicitly call dump_traceback() function and check its output.
+        Raise an error if the output doesn't match the expected format.
+        """
+        code = """
+            import faulthandler
+
+            filename = {filename!r}
+            fd = {fd}
+
+            def funcB():
+                if filename:
+                    with open(filename, "wb") as fp:
+                        faulthandler.dump_traceback(fp, all_threads=False)
+                elif fd is not None:
+                    faulthandler.dump_traceback(fd,
+                                                all_threads=False)
+                else:
+                    faulthandler.dump_traceback(all_threads=False)
+
+            def funcA():
+                funcB()
+
+            funcA()
+            """
+        code = code.format(
+            filename=filename,
+            fd=fd,
+        )
+        if filename:
+            lineno = 9
+        elif fd is not None:
+            lineno = 11
+        else:
+            lineno = 14
+        expected = [
+            'Stack (most recent call first):',
+            '  File "<string>", line %s in funcB' % lineno,
+            '  File "<string>", line 17 in funcA',
+            '  File "<string>", line 19 in <module>'
+        ]
+        trace, exitcode = self.get_output(code, filename, fd)
+        self.assertEqual(trace, expected)
+        self.assertEqual(exitcode, 0)
+
+    # TODO: RUSTPYTHON, AssertionError: Lists differ
+    @unittest.expectedFailure
+    def test_dump_traceback(self):
+        self.check_dump_traceback()
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_dump_traceback_file(self):
+        with temporary_filename() as filename:
+            self.check_dump_traceback(filename=filename)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @unittest.skipIf(sys.platform == "win32",
+                     "subprocess doesn't support pass_fds on Windows")
+    def test_dump_traceback_fd(self):
+        with tempfile.TemporaryFile('wb+') as fp:
+            self.check_dump_traceback(fd=fp.fileno())
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_truncate(self):
+        maxlen = 500
+        func_name = 'x' * (maxlen + 50)
+        truncated = 'x' * maxlen + '...'
+        code = """
+            import faulthandler
+
+            def {func_name}():
+                faulthandler.dump_traceback(all_threads=False)
+
+            {func_name}()
+            """
+        code = code.format(
+            func_name=func_name,
+        )
+        expected = [
+            'Stack (most recent call first):',
+            '  File "<string>", line 4 in %s' % truncated,
+            '  File "<string>", line 6 in <module>'
+        ]
+        trace, exitcode = self.get_output(code)
+        self.assertEqual(trace, expected)
+        self.assertEqual(exitcode, 0)
+
+    def check_dump_traceback_threads(self, filename):
+        """
+        Call explicitly dump_traceback(all_threads=True) and check the output.
+        Raise an error if the output doesn't match the expected format.
+        """
+        code = """
+            import faulthandler
+            from threading import Thread, Event
+            import time
+
+            def dump():
+                if {filename}:
+                    with open({filename}, "wb") as fp:
+                        faulthandler.dump_traceback(fp, all_threads=True)
+                else:
+                    faulthandler.dump_traceback(all_threads=True)
+
+            class Waiter(Thread):
+                # avoid blocking if the main thread raises an exception.
+                daemon = True
+
+                def __init__(self):
+                    Thread.__init__(self)
+                    self.running = Event()
+                    self.stop = Event()
+
+                def run(self):
+                    self.running.set()
+                    self.stop.wait()
+
+            waiter = Waiter()
+            waiter.start()
+            waiter.running.wait()
+            dump()
+            waiter.stop.set()
+            waiter.join()
+            """
+        code = code.format(filename=repr(filename))
+        output, exitcode = self.get_output(code, filename)
+        output = '\n'.join(output)
+        if filename:
+            lineno = 8
+        else:
+            lineno = 10
+        regex = r"""
+            ^Thread 0x[0-9a-f]+ \(most recent call first\):
+            (?:  File ".*threading.py", line [0-9]+ in [_a-z]+
+            ){{1,3}}  File "<string>", line 23 in run
+              File ".*threading.py", line [0-9]+ in _bootstrap_inner
+              File ".*threading.py", line [0-9]+ in _bootstrap
+
+            Current thread 0x[0-9a-f]+ \(most recent call first\):
+              File "<string>", line {lineno} in dump
+              File "<string>", line 28 in <module>$
+            """
+        regex = dedent(regex.format(lineno=lineno)).strip()
+        self.assertRegex(output, regex)
+        self.assertEqual(exitcode, 0)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_dump_traceback_threads(self):
+        self.check_dump_traceback_threads(None)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_dump_traceback_threads_file(self):
+        with temporary_filename() as filename:
+            self.check_dump_traceback_threads(filename)
+
+    def check_dump_traceback_later(self, repeat=False, cancel=False, loops=1,
+                                   *, filename=None, fd=None):
+        """
+        Check how many times the traceback is written in timeout x 2.5 seconds,
+        or timeout x 3.5 seconds if cancel is True: 1, 2 or 3 times depending
+        on repeat and cancel options.
+
+        Raise an error if the output doesn't match the expect format.
+        """
+        timeout_str = str(datetime.timedelta(seconds=TIMEOUT))
+        code = """
+            import faulthandler
+            import time
+            import sys
+
+            timeout = {timeout}
+            repeat = {repeat}
+            cancel = {cancel}
+            loops = {loops}
+            filename = {filename!r}
+            fd = {fd}
+
+            def func(timeout, repeat, cancel, file, loops):
+                for loop in range(loops):
+                    faulthandler.dump_traceback_later(timeout, repeat=repeat, file=file)
+                    if cancel:
+                        faulthandler.cancel_dump_traceback_later()
+                    time.sleep(timeout * 5)
+                    faulthandler.cancel_dump_traceback_later()
+
+            if filename:
+                file = open(filename, "wb")
+            elif fd is not None:
+                file = sys.stderr.fileno()
+            else:
+                file = None
+            func(timeout, repeat, cancel, file, loops)
+            if filename:
+                file.close()
+            """
+        code = code.format(
+            timeout=TIMEOUT,
+            repeat=repeat,
+            cancel=cancel,
+            loops=loops,
+            filename=filename,
+            fd=fd,
+        )
+        trace, exitcode = self.get_output(code, filename)
+        trace = '\n'.join(trace)
+
+        if not cancel:
+            count = loops
+            if repeat:
+                count *= 2
+            header = r'Timeout \(%s\)!\nThread 0x[0-9a-f]+ \(most recent call first\):\n' % timeout_str
+            regex = expected_traceback(17, 26, header, min_count=count)
+            self.assertRegex(trace, regex)
+        else:
+            self.assertEqual(trace, '')
+        self.assertEqual(exitcode, 0)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_dump_traceback_later(self):
+        self.check_dump_traceback_later()
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_dump_traceback_later_repeat(self):
+        self.check_dump_traceback_later(repeat=True)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_dump_traceback_later_cancel(self):
+        self.check_dump_traceback_later(cancel=True)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_dump_traceback_later_file(self):
+        with temporary_filename() as filename:
+            self.check_dump_traceback_later(filename=filename)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @unittest.skipIf(sys.platform == "win32",
+                     "subprocess doesn't support pass_fds on Windows")
+    def test_dump_traceback_later_fd(self):
+        with tempfile.TemporaryFile('wb+') as fp:
+            self.check_dump_traceback_later(fd=fp.fileno())
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_dump_traceback_later_twice(self):
+        self.check_dump_traceback_later(loops=2)
+
+    @unittest.skipIf(not hasattr(faulthandler, "register"),
+                     "need faulthandler.register")
+    def check_register(self, filename=False, all_threads=False,
+                       unregister=False, chain=False, fd=None):
+        """
+        Register a handler displaying the traceback on a user signal. Raise the
+        signal and check the written traceback.
+
+        If chain is True, check that the previous signal handler is called.
+
+        Raise an error if the output doesn't match the expected format.
+        """
+        signum = signal.SIGUSR1
+        code = """
+            import faulthandler
+            import os
+            import signal
+            import sys
+
+            all_threads = {all_threads}
+            signum = {signum:d}
+            unregister = {unregister}
+            chain = {chain}
+            filename = {filename!r}
+            fd = {fd}
+
+            def func(signum):
+                os.kill(os.getpid(), signum)
+
+            def handler(signum, frame):
+                handler.called = True
+            handler.called = False
+
+            if filename:
+                file = open(filename, "wb")
+            elif fd is not None:
+                file = sys.stderr.fileno()
+            else:
+                file = None
+            if chain:
+                signal.signal(signum, handler)
+            faulthandler.register(signum, file=file,
+                                  all_threads=all_threads, chain={chain})
+            if unregister:
+                faulthandler.unregister(signum)
+            func(signum)
+            if chain and not handler.called:
+                if file is not None:
+                    output = file
+                else:
+                    output = sys.stderr
+                print("Error: signal handler not called!", file=output)
+                exitcode = 1
+            else:
+                exitcode = 0
+            if filename:
+                file.close()
+            sys.exit(exitcode)
+            """
+        code = code.format(
+            all_threads=all_threads,
+            signum=signum,
+            unregister=unregister,
+            chain=chain,
+            filename=filename,
+            fd=fd,
+        )
+        trace, exitcode = self.get_output(code, filename)
+        trace = '\n'.join(trace)
+        if not unregister:
+            if all_threads:
+                regex = r'Current thread 0x[0-9a-f]+ \(most recent call first\):\n'
+            else:
+                regex = r'Stack \(most recent call first\):\n'
+            regex = expected_traceback(14, 32, regex)
+            self.assertRegex(trace, regex)
+        else:
+            self.assertEqual(trace, '')
+        if unregister:
+            self.assertNotEqual(exitcode, 0)
+        else:
+            self.assertEqual(exitcode, 0)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_register(self):
+        self.check_register()
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_unregister(self):
+        self.check_register(unregister=True)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_register_file(self):
+        with temporary_filename() as filename:
+            self.check_register(filename=filename)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    @unittest.skipIf(sys.platform == "win32",
+                     "subprocess doesn't support pass_fds on Windows")
+    def test_register_fd(self):
+        with tempfile.TemporaryFile('wb+') as fp:
+            self.check_register(fd=fp.fileno())
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_register_threads(self):
+        self.check_register(all_threads=True)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_register_chain(self):
+        self.check_register(chain=True)
+
+    @contextmanager
+    def check_stderr_none(self):
+        stderr = sys.stderr
+        try:
+            sys.stderr = None
+            with self.assertRaises(RuntimeError) as cm:
+                yield
+            self.assertEqual(str(cm.exception), "sys.stderr is None")
+        finally:
+            sys.stderr = stderr
+
+    # TODO: RUSTPYTHON, AssertionError: RuntimeError not raised
+    @unittest.expectedFailure
+    def test_stderr_None(self):
+        # Issue #21497: provide a helpful error if sys.stderr is None,
+        # instead of just an attribute error: "None has no attribute fileno".
+        with self.check_stderr_none():
+            faulthandler.enable()
+        with self.check_stderr_none():
+            faulthandler.dump_traceback()
+        with self.check_stderr_none():
+            faulthandler.dump_traceback_later(1e-3)
+        if hasattr(faulthandler, "register"):
+            with self.check_stderr_none():
+                faulthandler.register(signal.SIGUSR1)
+
+    # TODO: RUSTPYTHON, AttributeError: module 'msvcrt' has no attribute 'GetErrorMode'
+    @unittest.expectedFailure
+    @unittest.skipUnless(MS_WINDOWS, 'specific to Windows')
+    def test_raise_exception(self):
+        for exc, name in (
+            ('EXCEPTION_ACCESS_VIOLATION', 'access violation'),
+            ('EXCEPTION_INT_DIVIDE_BY_ZERO', 'int divide by zero'),
+            ('EXCEPTION_STACK_OVERFLOW', 'stack overflow'),
+        ):
+            self.check_windows_exception(f"""
+                import faulthandler
+                faulthandler.enable()
+                faulthandler._raise_exception(faulthandler._{exc})
+                """,
+                3,
+                name)
+
+    # TODO: RUSTPYTHON, AttributeError: module 'msvcrt' has no attribute 'GetErrorMode'
+    @unittest.expectedFailure
+    @unittest.skipUnless(MS_WINDOWS, 'specific to Windows')
+    def test_ignore_exception(self):
+        for exc_code in (
+            0xE06D7363,   # MSC exception ("Emsc")
+            0xE0434352,   # COM Callable Runtime exception ("ECCR")
+        ):
+            code = f"""
+                    import faulthandler
+                    faulthandler.enable()
+                    faulthandler._raise_exception({exc_code})
+                    """
+            code = dedent(code)
+            output, exitcode = self.get_output(code)
+            self.assertEqual(output, [])
+            self.assertEqual(exitcode, exc_code)
+
+    # TODO: RUSTPYTHON, AttributeError: module 'msvcrt' has no attribute 'GetErrorMode'
+    @unittest.expectedFailure
+    @unittest.skipUnless(MS_WINDOWS, 'specific to Windows')
+    def test_raise_nonfatal_exception(self):
+        # These exceptions are not strictly errors. Letting
+        # faulthandler display the traceback when they are
+        # raised is likely to result in noise. However, they
+        # may still terminate the process if there is no
+        # handler installed for them (which there typically
+        # is, e.g. for debug messages).
+        for exc in (
+            0x00000000,
+            0x34567890,
+            0x40000000,
+            0x40001000,
+            0x70000000,
+            0x7FFFFFFF,
+        ):
+            output, exitcode = self.get_output(f"""
+                import faulthandler
+                faulthandler.enable()
+                faulthandler._raise_exception(0x{exc:x})
+                """
+            )
+            self.assertEqual(output, [])
+            # On Windows older than 7 SP1, the actual exception code has
+            # bit 29 cleared.
+            self.assertIn(exitcode,
+                          (exc, exc & ~0x10000000))
+
+    # TODO: RUSTPYTHON, AttributeError: module 'msvcrt' has no attribute 'GetErrorMode'
+    @unittest.expectedFailure
+    @unittest.skipUnless(MS_WINDOWS, 'specific to Windows')
+    def test_disable_windows_exc_handler(self):
+        code = dedent("""
+            import faulthandler
+            faulthandler.enable()
+            faulthandler.disable()
+            code = faulthandler._EXCEPTION_ACCESS_VIOLATION
+            faulthandler._raise_exception(code)
+        """)
+        output, exitcode = self.get_output(code)
+        self.assertEqual(output, [])
+        self.assertEqual(exitcode, 0xC0000005)
+
+    # TODO: RUSTPYTHON, AssertionError: Lists differ
+    @unittest.expectedFailure
+    def test_cancel_later_without_dump_traceback_later(self):
+        # bpo-37933: Calling cancel_dump_traceback_later()
+        # without dump_traceback_later() must not segfault.
+        code = dedent("""
+            import faulthandler
+            faulthandler.cancel_dump_traceback_later()
+        """)
+        output, exitcode = self.get_output(code)
+        self.assertEqual(output, [])
+        self.assertEqual(exitcode, 0)
+
+
+if __name__ == "__main__":
+    unittest.main()