diff --git a/src/debugpy/_vendored/pydevd/_pydev_bundle/pydev_log.py b/src/debugpy/_vendored/pydevd/_pydev_bundle/pydev_log.py
index 981b54bd..71551956 100644
--- a/src/debugpy/_vendored/pydevd/_pydev_bundle/pydev_log.py
+++ b/src/debugpy/_vendored/pydevd/_pydev_bundle/pydev_log.py
@@ -1,4 +1,5 @@
-from _pydevd_bundle.pydevd_constants import DebugInfoHolder, SHOW_COMPILE_CYTHON_COMMAND_LINE, NULL, LOG_TIME
+from _pydevd_bundle.pydevd_constants import DebugInfoHolder, SHOW_COMPILE_CYTHON_COMMAND_LINE, NULL, LOG_TIME, \
+    ForkSafeLock
 from contextlib import contextmanager
 import traceback
 import os
@@ -6,18 +7,19 @@ import sys
 
 
 class _LoggingGlobals(object):
-
     _warn_once_map = {}
     _debug_stream_filename = None
-    _debug_stream = sys.stderr
+    _debug_stream = NULL
     _debug_stream_initialized = False
+    _initialize_lock = ForkSafeLock()
 
 
 def initialize_debug_stream(reinitialize=False):
     '''
     :param bool reinitialize:
         Reinitialize is used to update the debug stream after a fork (thus, if it wasn't
-        initialized, we don't need to do anything).
+        initialized, we don't need to do anything, just wait for the first regular log call
+        to initialize).
     '''
     if reinitialize:
         if not _LoggingGlobals._debug_stream_initialized:
@@ -26,32 +28,69 @@ def initialize_debug_stream(reinitialize=False):
         if _LoggingGlobals._debug_stream_initialized:
             return
 
-    _LoggingGlobals._debug_stream_initialized = True
+    with _LoggingGlobals._initialize_lock:
+        # Initialization is done lazilly, so, it's possible that multiple threads try to initialize
+        # logging.
 
-    # Note: we cannot initialize with sys.stderr because when forking we may end up logging things in 'os' calls.
-    _LoggingGlobals._debug_stream = NULL
-    _LoggingGlobals._debug_stream_filename = None
+        # Check initial conditions again after obtaining the lock.
+        if reinitialize:
+            if not _LoggingGlobals._debug_stream_initialized:
+                return
+        else:
+            if _LoggingGlobals._debug_stream_initialized:
+                return
 
-    if not DebugInfoHolder.PYDEVD_DEBUG_FILE:
-        _LoggingGlobals._debug_stream = sys.stderr
-    else:
-        # Add pid to the filename.
-        try:
-            dirname = os.path.dirname(DebugInfoHolder.PYDEVD_DEBUG_FILE)
-            basename = os.path.basename(DebugInfoHolder.PYDEVD_DEBUG_FILE)
-            try:
-                os.makedirs(dirname)
-            except:
-                pass  # Ignore error if it already exists.
+        _LoggingGlobals._debug_stream_initialized = True
 
-            name, ext = os.path.splitext(basename)
-            debug_file = os.path.join(dirname, name + '.' + str(os.getpid()) + ext)
-            _LoggingGlobals._debug_stream = open(debug_file, 'w')
-            _LoggingGlobals._debug_stream_filename = debug_file
-        except:
+        # Note: we cannot initialize with sys.stderr because when forking we may end up logging things in 'os' calls.
+        _LoggingGlobals._debug_stream = NULL
+        _LoggingGlobals._debug_stream_filename = None
+
+        if not DebugInfoHolder.PYDEVD_DEBUG_FILE:
             _LoggingGlobals._debug_stream = sys.stderr
-            # Don't fail when trying to setup logging, just show the exception.
-            traceback.print_exc()
+        else:
+            # Add pid to the filename.
+            try:
+                target_file = DebugInfoHolder.PYDEVD_DEBUG_FILE
+                debug_file = _compute_filename_with_pid(target_file)
+                _LoggingGlobals._debug_stream = open(debug_file, 'w')
+                _LoggingGlobals._debug_stream_filename = debug_file
+            except Exception:
+                _LoggingGlobals._debug_stream = sys.stderr
+                # Don't fail when trying to setup logging, just show the exception.
+                traceback.print_exc()
+
+
+def _compute_filename_with_pid(target_file, pid=None):
+    # Note: used in tests.
+    dirname = os.path.dirname(target_file)
+    basename = os.path.basename(target_file)
+    try:
+        os.makedirs(dirname)
+    except Exception:
+        pass  # Ignore error if it already exists.
+
+    name, ext = os.path.splitext(basename)
+    if pid is None:
+        pid = os.getpid()
+    return os.path.join(dirname, '%s.%s%s' % (name, pid, ext))
+
+
+def log_to(log_file:str, log_level:int=3) -> None:
+    with _LoggingGlobals._initialize_lock:
+        # Can be set directly.
+        DebugInfoHolder.DEBUG_TRACE_LEVEL = log_level
+
+        if DebugInfoHolder.PYDEVD_DEBUG_FILE != log_file:
+            # Note that we don't need to reset it unless it actually changed
+            # (would be the case where it's set as an env var in a new process
+            # and a subprocess initializes logging to the same value).
+            _LoggingGlobals._debug_stream = NULL
+            _LoggingGlobals._debug_stream_filename = None
+
+            DebugInfoHolder.PYDEVD_DEBUG_FILE = log_file
+
+            _LoggingGlobals._debug_stream_initialized = False
 
 
 def list_log_files(pydevd_debug_file):
@@ -71,28 +110,33 @@ def log_context(trace_level, stream):
     '''
     To be used to temporarily change the logging settings.
     '''
-    original_trace_level = DebugInfoHolder.DEBUG_TRACE_LEVEL
-    original_debug_stream = _LoggingGlobals._debug_stream
-    original_pydevd_debug_file = DebugInfoHolder.PYDEVD_DEBUG_FILE
-    original_debug_stream_filename = _LoggingGlobals._debug_stream_filename
-    original_initialized = _LoggingGlobals._debug_stream_initialized
+    with _LoggingGlobals._initialize_lock:
+        original_trace_level = DebugInfoHolder.DEBUG_TRACE_LEVEL
+        original_debug_stream = _LoggingGlobals._debug_stream
+        original_pydevd_debug_file = DebugInfoHolder.PYDEVD_DEBUG_FILE
+        original_debug_stream_filename = _LoggingGlobals._debug_stream_filename
+        original_initialized = _LoggingGlobals._debug_stream_initialized
 
-    DebugInfoHolder.DEBUG_TRACE_LEVEL = trace_level
-    _LoggingGlobals._debug_stream = stream
-    _LoggingGlobals._debug_stream_initialized = True
+        DebugInfoHolder.DEBUG_TRACE_LEVEL = trace_level
+        _LoggingGlobals._debug_stream = stream
+        _LoggingGlobals._debug_stream_initialized = True
     try:
         yield
     finally:
-        DebugInfoHolder.DEBUG_TRACE_LEVEL = original_trace_level
-        _LoggingGlobals._debug_stream = original_debug_stream
-        DebugInfoHolder.PYDEVD_DEBUG_FILE = original_pydevd_debug_file
-        _LoggingGlobals._debug_stream_filename = original_debug_stream_filename
-        _LoggingGlobals._debug_stream_initialized = original_initialized
+        with _LoggingGlobals._initialize_lock:
+            DebugInfoHolder.DEBUG_TRACE_LEVEL = original_trace_level
+            _LoggingGlobals._debug_stream = original_debug_stream
+            DebugInfoHolder.PYDEVD_DEBUG_FILE = original_pydevd_debug_file
+            _LoggingGlobals._debug_stream_filename = original_debug_stream_filename
+            _LoggingGlobals._debug_stream_initialized = original_initialized
 
 
 import time
 _last_log_time = time.time()
 
+# Set to True to show pid in each logged message (usually the file has it, but sometimes it's handy).
+_LOG_PID = False
+
 
 def _pydevd_log(level, msg, *args):
     '''
@@ -120,6 +164,10 @@ def _pydevd_log(level, msg, *args):
                 msg = '%.2fs - %s\n' % (time_diff, msg,)
             else:
                 msg = '%s\n' % (msg,)
+
+            if _LOG_PID:
+                msg = '<%s> - %s\n' % (os.getpid(), msg,)
+
             try:
                 try:
                     initialize_debug_stream()  # Do it as late as possible
diff --git a/src/debugpy/_vendored/pydevd/_pydev_bundle/pydev_monkey.py b/src/debugpy/_vendored/pydevd/_pydev_bundle/pydev_monkey.py
index 306a450f..9f6c15fe 100644
--- a/src/debugpy/_vendored/pydevd/_pydev_bundle/pydev_monkey.py
+++ b/src/debugpy/_vendored/pydevd/_pydev_bundle/pydev_monkey.py
@@ -4,7 +4,7 @@ import re
 import sys
 from _pydev_bundle._pydev_saved_modules import threading
 from _pydevd_bundle.pydevd_constants import get_global_debugger, IS_WINDOWS, IS_JYTHON, get_current_thread_id, \
-    sorted_dict_repr, set_global_debugger
+    sorted_dict_repr, set_global_debugger, DebugInfoHolder
 from _pydev_bundle import pydev_log
 from contextlib import contextmanager
 from _pydevd_bundle import pydevd_constants
@@ -68,6 +68,13 @@ def _get_setup_updated_with_protocol_and_ppid(setup, is_exec=False):
 
     else:
         pydev_log.debug('Unexpected protocol: %s', protocol)
+
+    if DebugInfoHolder.PYDEVD_DEBUG_FILE:
+        setup['log-file'] = DebugInfoHolder.PYDEVD_DEBUG_FILE
+
+    if DebugInfoHolder.DEBUG_TRACE_LEVEL:
+        setup['log-level'] = DebugInfoHolder.DEBUG_TRACE_LEVEL
+
     return setup
 
 
diff --git a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_api.py b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_api.py
index 28a28d6d..4015152b 100644
--- a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_api.py
+++ b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_api.py
@@ -551,8 +551,7 @@ class PyDevdAPI(object):
         if not supported_type:
             raise NameError(breakpoint_type)
 
-        if DebugInfoHolder.DEBUG_TRACE_BREAKPOINTS > 0:
-            pydev_log.debug('Added breakpoint:%s - line:%s - func_name:%s\n', canonical_normalized_filename, line, func_name)
+        pydev_log.debug('Added breakpoint:%s - line:%s - func_name:%s\n', canonical_normalized_filename, line, func_name)
 
         if canonical_normalized_filename in file_to_id_to_breakpoint:
             id_to_pybreakpoint = file_to_id_to_breakpoint[canonical_normalized_filename]
@@ -672,10 +671,10 @@ class PyDevdAPI(object):
         else:
             try:
                 id_to_pybreakpoint = file_to_id_to_breakpoint.get(canonical_normalized_filename, {})
-                if DebugInfoHolder.DEBUG_TRACE_BREAKPOINTS > 0:
+                if DebugInfoHolder.DEBUG_TRACE_LEVEL >= 1:
                     existing = id_to_pybreakpoint[breakpoint_id]
                     pydev_log.info('Removed breakpoint:%s - line:%s - func_name:%s (id: %s)\n' % (
-                        canonical_normalized_filename, existing.line, existing.func_name.encode('utf-8'), breakpoint_id))
+                        canonical_normalized_filename, existing.line, existing.func_name, breakpoint_id))
 
                 del id_to_pybreakpoint[breakpoint_id]
                 py_db.consolidate_breakpoints(canonical_normalized_filename, id_to_pybreakpoint, file_to_line_to_breakpoints)
diff --git a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py
index 930adda8..163fd7ab 100644
--- a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py
+++ b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py
@@ -274,13 +274,14 @@ class ReaderThread(PyDBDaemonThread):
                 if hasattr(line, 'decode'):
                     line = line.decode('utf-8')
 
-                if DebugInfoHolder.DEBUG_RECORD_SOCKET_READS:
-                    pydev_log.critical(u'debugger: received >>%s<<\n' % (line,))
+                if DebugInfoHolder.DEBUG_TRACE_LEVEL >= 3:
+                    pydev_log.debug('debugger: received >>%s<<\n', line)
 
-                args = line.split(u'\t', 2)
+                args = line.split('\t', 2)
                 try:
                     cmd_id = int(args[0])
-                    pydev_log.debug('Received command: %s %s\n' % (ID_TO_MEANING.get(str(cmd_id), '???'), line,))
+                    if DebugInfoHolder.DEBUG_TRACE_LEVEL >= 3:
+                        pydev_log.debug('Received command: %s %s\n', ID_TO_MEANING.get(str(cmd_id), '???'), line)
                     self.process_command(cmd_id, int(args[1]), args[2])
                 except:
                     if sys is not None and pydev_log_exception is not None:  # Could happen at interpreter shutdown
@@ -1351,12 +1352,12 @@ def internal_get_completions(dbg, seq, thread_id, frame_id, act_tok, line=-1, co
     try:
         remove_path = None
         try:
-            qualifier = u''
+            qualifier = ''
             if column >= 0:
                 token_and_qualifier = extract_token_and_qualifier(act_tok, line, column)
                 act_tok = token_and_qualifier[0]
                 if act_tok:
-                    act_tok += u'.'
+                    act_tok += '.'
                 qualifier = token_and_qualifier[1]
 
             frame = dbg.find_frame(thread_id, frame_id)
diff --git a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_command_line_handling.py b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_command_line_handling.py
index 2fe9a614..ea7f745f 100644
--- a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_command_line_handling.py
+++ b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_command_line_handling.py
@@ -1,4 +1,5 @@
 import os
+import sys
 
 
 class ArgHandlerWithParam:
@@ -68,8 +69,11 @@ ACCEPTED_ARG_HANDLERS = [
     ArgHandlerWithParam('access-token'),
     ArgHandlerWithParam('client-access-token'),
 
+    # Logging
+    ArgHandlerWithParam('log-file'),
+    ArgHandlerWithParam('log-level', int, 0),
+
     ArgHandlerBool('server'),
-    ArgHandlerBool('DEBUG_RECORD_SOCKET_READS'),
     ArgHandlerBool('multiproc'),  # Used by PyCharm (reuses connection: ssh tunneling)
     ArgHandlerBool('multiprocess'),  # Used by PyDev (creates new connection to ide)
     ArgHandlerBool('save-signatures'),
@@ -132,6 +136,8 @@ def process_command_line(argv):
     setup['file'] = ''
     setup['qt-support'] = ''
 
+    initial_argv = tuple(argv)
+
     i = 0
     del argv[0]
     while i < len(argv):
@@ -169,10 +175,9 @@ def process_command_line(argv):
             i = len(argv)  # pop out, file is our last argument
 
         elif argv[i] == '--DEBUG':
-            from pydevd import set_debug
-            del argv[i]
-            set_debug(setup)
+            sys.stderr.write('pydevd: --DEBUG parameter deprecated. Use `--debug-level=3` instead.\n')
 
         else:
-            raise ValueError("Unexpected option: " + argv[i])
+            raise ValueError("Unexpected option: %s when processing: %s" % (argv[i], initial_argv))
     return setup
+
diff --git a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_constants.py b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_constants.py
index 1b36524e..013b6cf8 100644
--- a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_constants.py
+++ b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_constants.py
@@ -39,10 +39,6 @@ class DebugInfoHolder:
     # General information
     DEBUG_TRACE_LEVEL = 0  # 0 = critical, 1 = info, 2 = debug, 3 = verbose
 
-    # Flags to debug specific points of the code.
-    DEBUG_RECORD_SOCKET_READS = False
-    DEBUG_TRACE_BREAKPOINTS = -1
-
     PYDEVD_DEBUG_FILE = None
 
 
@@ -292,7 +288,6 @@ DEFAULT_VALUE = "__pydevd_value_async"
 ASYNC_EVAL_TIMEOUT_SEC = 60
 NEXT_VALUE_SEPARATOR = "__pydev_val__"
 BUILTINS_MODULE_NAME = 'builtins'
-SHOW_DEBUG_INFO_ENV = is_true_in_env(('PYCHARM_DEBUG', 'PYDEV_DEBUG', 'PYDEVD_DEBUG'))
 
 # Pandas customization.
 PANDAS_MAX_ROWS = as_int_in_env('PYDEVD_PANDAS_MAX_ROWS', 60)
@@ -335,11 +330,11 @@ EXCEPTION_TYPE_UNHANDLED = 'UNHANDLED'
 EXCEPTION_TYPE_USER_UNHANDLED = 'USER_UNHANDLED'
 EXCEPTION_TYPE_HANDLED = 'HANDLED'
 
+SHOW_DEBUG_INFO_ENV = is_true_in_env(('PYCHARM_DEBUG', 'PYDEV_DEBUG', 'PYDEVD_DEBUG'))
+
 if SHOW_DEBUG_INFO_ENV:
     # show debug info before the debugger start
-    DebugInfoHolder.DEBUG_RECORD_SOCKET_READS = True
     DebugInfoHolder.DEBUG_TRACE_LEVEL = 3
-    DebugInfoHolder.DEBUG_TRACE_BREAKPOINTS = 1
 
 DebugInfoHolder.PYDEVD_DEBUG_FILE = os.getenv('PYDEVD_DEBUG_FILE')
 
diff --git a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_process_net_command_json.py b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_process_net_command_json.py
index ff01ecd3..c305c6da 100644
--- a/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_process_net_command_json.py
+++ b/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_process_net_command_json.py
@@ -163,7 +163,7 @@ class PyDevJsonCommandProcessor(object):
                 return NetCommand(CMD_RETURN, 0, error_response, is_json=True)
 
         else:
-            if DebugInfoHolder.DEBUG_RECORD_SOCKET_READS and DebugInfoHolder.DEBUG_TRACE_LEVEL >= 1:
+            if DebugInfoHolder.DEBUG_TRACE_LEVEL >= 1:
                 pydev_log.info('Process %s: %s\n' % (
                     request.__class__.__name__, json.dumps(request.to_dict(update_ids_to_dap=True), indent=4, sort_keys=True),))
 
diff --git a/src/debugpy/_vendored/pydevd/pydevd.py b/src/debugpy/_vendored/pydevd/pydevd.py
index 67382dee..64520310 100644
--- a/src/debugpy/_vendored/pydevd/pydevd.py
+++ b/src/debugpy/_vendored/pydevd/pydevd.py
@@ -64,11 +64,11 @@ from _pydevd_bundle.pydevd_extension_api import DebuggerEventHandler
 from _pydevd_bundle.pydevd_frame_utils import add_exception_to_frame, remove_exception_from_frame
 from _pydevd_bundle.pydevd_net_command_factory_xml import NetCommandFactory
 from _pydevd_bundle.pydevd_trace_dispatch import (
-    trace_dispatch as _trace_dispatch, global_cache_skips, global_cache_frame_skips, fix_top_level_trace_and_get_trace_func)
+    trace_dispatch as _trace_dispatch, global_cache_skips, global_cache_frame_skips, fix_top_level_trace_and_get_trace_func, USING_CYTHON)
 from _pydevd_bundle.pydevd_utils import save_main_module, is_current_thread_main_thread, \
     import_attr_from_module
 from _pydevd_frame_eval.pydevd_frame_eval_main import (
-    frame_eval_func, dummy_trace_dispatch)
+    frame_eval_func, dummy_trace_dispatch, USING_FRAME_EVAL)
 import pydev_ipython  # @UnusedImport
 from _pydevd_bundle.pydevd_source_mapping import SourceMapping
 from _pydevd_bundle.pydevd_concurrency_analyser.pydevd_concurrency_logger import ThreadingLogger, AsyncioLogger, send_concurrency_message, cur_time
@@ -1814,22 +1814,19 @@ class PyDB(object):
         if eb.notify_on_unhandled_exceptions:
             cp = self.break_on_uncaught_exceptions.copy()
             cp[exception] = eb
-            if DebugInfoHolder.DEBUG_TRACE_BREAKPOINTS > 0:
-                pydev_log.critical("Exceptions to hook on terminate: %s.", cp)
+            pydev_log.info("Exceptions to hook on terminate: %s.", cp)
             self.break_on_uncaught_exceptions = cp
 
         if eb.notify_on_handled_exceptions:
             cp = self.break_on_caught_exceptions.copy()
             cp[exception] = eb
-            if DebugInfoHolder.DEBUG_TRACE_BREAKPOINTS > 0:
-                pydev_log.critical("Exceptions to hook always: %s.", cp)
+            pydev_log.info("Exceptions to hook always: %s.", cp)
             self.break_on_caught_exceptions = cp
 
         if eb.notify_on_user_unhandled_exceptions:
             cp = self.break_on_user_uncaught_exceptions.copy()
             cp[exception] = eb
-            if DebugInfoHolder.DEBUG_TRACE_BREAKPOINTS > 0:
-                pydev_log.critical("Exceptions to hook on user uncaught code: %s.", cp)
+            pydev_log.info("Exceptions to hook on user uncaught code: %s.", cp)
             self.break_on_user_uncaught_exceptions = cp
 
         return eb
@@ -2600,12 +2597,6 @@ def send_json_message(msg):
     return True
 
 
-def set_debug(setup):
-    setup['DEBUG_RECORD_SOCKET_READS'] = True
-    setup['DEBUG_TRACE_BREAKPOINTS'] = 1
-    setup['DEBUG_TRACE_LEVEL'] = 3
-
-
 def enable_qt_support(qt_support_mode):
     from _pydev_bundle import pydev_monkey_qt
     pydev_monkey_qt.patch_qt(qt_support_mode)
@@ -3239,14 +3230,40 @@ for handler in pydevd_extension_utils.extensions_of_type(DebuggerEventHandler):
     handler.on_debugger_modules_loaded(debugger_version=__version__)
 
 
+def log_to(log_file:str, log_level=3) -> None:
+    '''
+    In pydevd it's possible to log by setting the following environment variables:
+
+    PYDEVD_DEBUG=1 (sets the default log level to 3 along with other default options)
+    PYDEVD_DEBUG_FILE=</path/to/file.log>
+
+    Note that the file will have the pid of the process added to it (so, logging to
+    /path/to/file.log would actually start logging to /path/to/file.<pid>.log -- if subprocesses are
+    logged, each new subprocess will have the logging set to its own pid).
+
+    Usually setting the environment variable is preferred as it'd log information while
+    pydevd is still doing its imports and not just after this method is called, but on
+    cases where this is hard to do this function may be called to set the tracing after
+    pydevd itself is already imported.
+    '''
+    pydev_log.log_to(log_file, log_level)
+
+
+def _log_initial_info():
+    pydev_log.debug("Initial arguments: %s", (sys.argv,))
+    pydev_log.debug("Current pid: %s", os.getpid())
+    pydev_log.debug("Using cython: %s", USING_CYTHON)
+    pydev_log.debug("Using frame eval: %s", USING_FRAME_EVAL)
+    pydev_log.debug("Using gevent mode: %s / imported gevent module support: %s", SUPPORT_GEVENT, bool(pydevd_gevent_integration))
+
+
 #=======================================================================================================================
 # main
 #=======================================================================================================================
 def main():
 
     # parse the command line. --file is our last argument that is required
-    pydev_log.debug("Initial arguments: %s", (sys.argv,))
-    pydev_log.debug("Current pid: %s", os.getpid())
+    _log_initial_info()
     try:
         from _pydevd_bundle.pydevd_command_line_handling import process_command_line
         setup = process_command_line(sys.argv)
@@ -3255,6 +3272,24 @@ def main():
         pydev_log.exception()
         usage(1)
 
+    log_trace_level = setup.get('log-level')
+
+    # Note: the logging info could've been changed (this would happen if this is a
+    # subprocess and the value in the environment variable does not match the value in the
+    # argument because the user used `pydevd.log_to` instead of supplying the environment
+    # variable). If this is the case, update the logging info and re-log some information
+    # in the new target.
+    new_debug_file = setup.get('log-file')
+    if new_debug_file and DebugInfoHolder.PYDEVD_DEBUG_FILE != new_debug_file:
+        # The debug file can't be set directly, we need to use log_to() so that the a
+        # new stream is actually created for the new file.
+        log_to(new_debug_file, log_trace_level if log_trace_level is not None else 3)
+        _log_initial_info()  # The redirection info just changed, log it again.
+
+    elif log_trace_level is not None:
+        # The log file was not specified
+        DebugInfoHolder.DEBUG_TRACE_LEVEL = log_trace_level
+
     if setup['print-in-debugger-startup']:
         try:
             pid = ' (pid: %s)' % os.getpid()
@@ -3267,13 +3302,6 @@ def main():
 
     pydevd_vm_type.setup_type(setup.get('vm_type', None))
 
-    if SHOW_DEBUG_INFO_ENV:
-        set_debug(setup)
-
-    DebugInfoHolder.DEBUG_RECORD_SOCKET_READS = setup.get('DEBUG_RECORD_SOCKET_READS', DebugInfoHolder.DEBUG_RECORD_SOCKET_READS)
-    DebugInfoHolder.DEBUG_TRACE_BREAKPOINTS = setup.get('DEBUG_TRACE_BREAKPOINTS', DebugInfoHolder.DEBUG_TRACE_BREAKPOINTS)
-    DebugInfoHolder.DEBUG_TRACE_LEVEL = setup.get('DEBUG_TRACE_LEVEL', DebugInfoHolder.DEBUG_TRACE_LEVEL)
-
     port = setup['port']
     host = setup['client']
     f = setup['file']
diff --git a/src/debugpy/_vendored/pydevd/pydevd_attach_to_process/attach_script.py b/src/debugpy/_vendored/pydevd/pydevd_attach_to_process/attach_script.py
index c8ad0037..9c636a47 100644
--- a/src/debugpy/_vendored/pydevd/pydevd_attach_to_process/attach_script.py
+++ b/src/debugpy/_vendored/pydevd/pydevd_attach_to_process/attach_script.py
@@ -168,8 +168,6 @@ def attach(port, host, protocol=''):
         if py_db is not None:
             py_db.dispose_and_kill_all_pydevd_threads(wait=False)
 
-        # pydevd.DebugInfoHolder.DEBUG_RECORD_SOCKET_READS = True
-        # pydevd.DebugInfoHolder.DEBUG_TRACE_BREAKPOINTS = 3
         # pydevd.DebugInfoHolder.DEBUG_TRACE_LEVEL = 3
         pydevd.settrace(
             port=port,
diff --git a/src/debugpy/_vendored/pydevd/tests_python/debugger_fixtures.py b/src/debugpy/_vendored/pydevd/tests_python/debugger_fixtures.py
index 8a337cf8..2ab0d23e 100644
--- a/src/debugpy/_vendored/pydevd/tests_python/debugger_fixtures.py
+++ b/src/debugpy/_vendored/pydevd/tests_python/debugger_fixtures.py
@@ -418,7 +418,7 @@ def case_setup_multiprocessing(debugger_runner_simple):
 
             def update_command_line_args(writer, args):
                 ret = debugger_unittest.AbstractWriterThread.update_command_line_args(writer, args)
-                ret.insert(ret.index('--DEBUG_RECORD_SOCKET_READS'), '--multiprocess')
+                ret.insert(ret.index('--client'), '--multiprocess')
                 return ret
 
             WriterThread.update_command_line_args = update_command_line_args
diff --git a/src/debugpy/_vendored/pydevd/tests_python/debugger_unittest.py b/src/debugpy/_vendored/pydevd/tests_python/debugger_unittest.py
index d7c77546..bdf7008c 100644
--- a/src/debugpy/_vendored/pydevd/tests_python/debugger_unittest.py
+++ b/src/debugpy/_vendored/pydevd/tests_python/debugger_unittest.py
@@ -397,7 +397,6 @@ class DebuggerRunner(object):
         localhost = pydev_localhost.get_localhost()
         ret = [
             writer.get_pydevd_file(),
-            '--DEBUG_RECORD_SOCKET_READS',
         ]
 
         if not IS_PY36_OR_GREATER or not IS_CPYTHON or not TEST_CYTHON:
diff --git a/src/debugpy/_vendored/pydevd/tests_python/resources/_debugger_case_logging.py b/src/debugpy/_vendored/pydevd/tests_python/resources/_debugger_case_logging.py
new file mode 100644
index 00000000..b6355b86
--- /dev/null
+++ b/src/debugpy/_vendored/pydevd/tests_python/resources/_debugger_case_logging.py
@@ -0,0 +1,63 @@
+import subprocess
+import sys
+import json
+from _pydev_bundle import pydev_log
+import os
+import io
+
+
+def gen_debug_info():
+    from _pydevd_bundle.pydevd_constants import DebugInfoHolder
+    dct = {}
+    for name in (
+        'PYDEVD_DEBUG_FILE',
+        'DEBUG_TRACE_LEVEL',
+        ):
+        dct[name] = getattr(DebugInfoHolder, name)
+
+    return dct
+
+
+if __name__ == "__main__":
+    if '-print-debug' in sys.argv:
+        info = gen_debug_info()  # break on 2nd process
+        pydev_log.info('Something in print-debug')
+
+        print('>>> print-debug pid: %s' % os.getpid())
+        print(json.dumps(info))
+
+    else:
+        # Note: when running tests we usually have logging setup,
+        # so, we create a context so that our changes are restored
+        # when it finishes (as the `log_to` function will just reset
+        # whatever is there).
+        s = io.StringIO()
+        with pydev_log.log_context(trace_level=3, stream=s):
+            target_log_file = os.getenv('TARGET_LOG_FILE')
+
+            pydev_log.log_to(target_log_file, 1)
+            new_debug_info = gen_debug_info()
+            subprocess_pid = None
+            with subprocess.Popen(
+                    [sys.executable, __file__, '-print-debug'],
+                    stdout=subprocess.PIPE,
+                    stderr=subprocess.PIPE,
+                ) as process:
+                subprocess_pid = process.pid
+                stdout, stderr = process.communicate(input)
+
+            output = stdout.decode('utf-8')
+            pydev_log.info('Something in initial')
+
+        log_contents = open(pydev_log._compute_filename_with_pid(target_log_file)).read()
+        assert 'Something in initial' in log_contents, 'Did not find "Something in initial" in %s' % (log_contents,)
+
+        log_contents = open(pydev_log._compute_filename_with_pid(target_log_file, pid=subprocess_pid)).read()
+        assert 'Something in print-debug' in log_contents, 'Did not find "Something in print-debug" in %s' % (log_contents,)
+
+        output = ''.join(output.splitlines(keepends=True)[1:])  # Remove the first line
+        loaded_debug_info = json.loads(output)
+        assert loaded_debug_info == new_debug_info, 'Expected %s. Found: %s' % (new_debug_info, loaded_debug_info)
+        print('>>> Initial pid: %s' % os.getpid())
+        print(output)
+        print('TEST SUCEEDED')
diff --git a/src/debugpy/_vendored/pydevd/tests_python/test_debugger.py b/src/debugpy/_vendored/pydevd/tests_python/test_debugger.py
index 567983ba..9262185d 100644
--- a/src/debugpy/_vendored/pydevd/tests_python/test_debugger.py
+++ b/src/debugpy/_vendored/pydevd/tests_python/test_debugger.py
@@ -3836,10 +3836,12 @@ def test_step_over_my_code_global_setting_and_explicit_include(case_setup):
 def test_access_token(case_setup):
 
     def update_command_line_args(self, args):
-        args.insert(2, '--access-token')
-        args.insert(3, 'bar123')
-        args.insert(2, '--client-access-token')
-        args.insert(3, 'foo234')
+        i = args.index('--client')
+        assert i > 0
+        args.insert(i, '--access-token')
+        args.insert(i + 1, 'bar123')
+        args.insert(i, '--client-access-token')
+        args.insert(i + 1, 'foo234')
         return args
 
     with case_setup.test_file('_debugger_case_print.py', update_command_line_args=update_command_line_args) as writer:
diff --git a/src/debugpy/_vendored/pydevd/tests_python/test_debugger_json.py b/src/debugpy/_vendored/pydevd/tests_python/test_debugger_json.py
index 6d0d4015..73ea3258 100644
--- a/src/debugpy/_vendored/pydevd/tests_python/test_debugger_json.py
+++ b/src/debugpy/_vendored/pydevd/tests_python/test_debugger_json.py
@@ -4130,8 +4130,8 @@ def test_ppid(case_setup, pyfile):
 
     def update_command_line_args(writer, args):
         ret = debugger_unittest.AbstractWriterThread.update_command_line_args(writer, args)
-        ret.insert(ret.index('--DEBUG_RECORD_SOCKET_READS'), '--ppid')
-        ret.insert(ret.index('--DEBUG_RECORD_SOCKET_READS'), '22')
+        ret.insert(ret.index('--client'), '--ppid')
+        ret.insert(ret.index('--client'), '22')
         return ret
 
     with case_setup.test_file(
@@ -4937,7 +4937,7 @@ def test_no_subprocess_patching(case_setup_multiprocessing, apply_multiprocessin
 
     def update_command_line_args(writer, args):
         ret = debugger_unittest.AbstractWriterThread.update_command_line_args(writer, args)
-        ret.insert(ret.index('--DEBUG_RECORD_SOCKET_READS'), '--multiprocess')
+        ret.insert(ret.index('--client'), '--multiprocess')
         if apply_multiprocessing_patch:
             ret.append('apply-multiprocessing-patch')
         return ret
@@ -6304,6 +6304,72 @@ def test_ipython_stepping_step_in(case_setup):
         writer.finished_ok = True
 
 
+def test_logging_api(case_setup_multiprocessing, tmpdir):
+    import threading
+    from tests_python.debugger_unittest import AbstractWriterThread
+
+    log_file = str(tmpdir.join('pydevd_in_test_logging.log'))
+
+    def get_environ(self):
+        env = os.environ.copy()
+        env["TARGET_LOG_FILE"] = log_file
+        return env
+
+    with case_setup_multiprocessing.test_file(
+            '_debugger_case_logging.py',
+            get_environ=get_environ
+        ) as writer:
+        json_facade = JsonFacade(writer)
+        json_facade.write_launch()
+
+        break1_line = writer.get_line_index_with_content("break on 2nd process")
+        json_facade.write_set_breakpoints([break1_line])
+
+        server_socket = writer.server_socket
+        secondary_finished_ok = [False]
+
+        class SecondaryProcessWriterThread(AbstractWriterThread):
+
+            TEST_FILE = writer.get_main_filename()
+            _sequence = -1
+
+        class SecondaryProcessThreadCommunication(threading.Thread):
+
+            def run(self):
+                from tests_python.debugger_unittest import ReaderThread
+                server_socket.listen(1)
+                self.server_socket = server_socket
+                new_sock, addr = server_socket.accept()
+
+                reader_thread = ReaderThread(new_sock)
+                reader_thread.name = '  *** Multiprocess Reader Thread'
+                reader_thread.start()
+
+                writer2 = SecondaryProcessWriterThread()
+                writer2.reader_thread = reader_thread
+                writer2.sock = new_sock
+                json_facade2 = JsonFacade(writer2)
+
+                json_facade2.write_set_breakpoints([break1_line, ])
+                json_facade2.write_make_initial_run()
+
+                json_facade2.wait_for_thread_stopped()
+                json_facade2.write_continue()
+                secondary_finished_ok[0] = True
+
+        secondary_process_thread_communication = SecondaryProcessThreadCommunication()
+        secondary_process_thread_communication.start()
+        time.sleep(.1)
+
+        json_facade.write_make_initial_run()
+        secondary_process_thread_communication.join(10)
+        if secondary_process_thread_communication.is_alive():
+            raise AssertionError('The SecondaryProcessThreadCommunication did not finish')
+
+        assert secondary_finished_ok[0]
+        writer.finished_ok = True
+
+
 if __name__ == '__main__':
     pytest.main(['-k', 'test_replace_process', '-s'])
 
diff --git a/src/debugpy/_vendored/pydevd/tests_python/test_utilities.py b/src/debugpy/_vendored/pydevd/tests_python/test_utilities.py
index b9dfbe33..09b8b19d 100644
--- a/src/debugpy/_vendored/pydevd/tests_python/test_utilities.py
+++ b/src/debugpy/_vendored/pydevd/tests_python/test_utilities.py
@@ -255,10 +255,7 @@ def _check_tracing_other_threads():
     import pydevd_tracing
     import time
     from tests_python.debugger_unittest import wait_for_condition
-    try:
-        import _thread
-    except ImportError:
-        import thread as _thread
+    import _thread
 
     # This method is called in a subprocess, so, make sure we exit properly even if we somehow
     # deadlock somewhere else.