Fix #304: Breakpoints not working with QThread/PySide2

Expose pydevd.enable_qt_support() in debugpy.server via debugpy.configure(qt=...) and --configure-qt ...

Expose the same in debugpy.adapter via "qt" debug configuration property.

Default to "auto" for all of the above, and also provide "none" to disable Qt monkey-patching entirely.

src/debugpy/launcher/handlers.py

@@ -49,8 +49,18 @@ def property_or_debug_option(prop_name, flag_name):
             "--connect",
             launcher.adapter_host + ":" + str(port),
         ]
+
         if not request("subProcess", True):
             cmdline += ["--configure-subProcess", "False"]
+
+        qt_mode = request(
+            "qt",
+            json.enum(
+                "auto", "none", "pyside", "pyside2", "pyqt4", "pyqt5", optional=True
+            ),
+        )
+        cmdline += ["--configure-qt", qt_mode]
+
         adapter_access_token = request("adapterAccessToken", unicode, optional=True)
         if adapter_access_token != ():
             cmdline += ["--adapter-access-token", compat.filename(adapter_access_token)]

src/debugpy/server/api.py

@@ -22,7 +22,16 @@
 _tls = threading.local()
 
 # TODO: "gevent", if possible.
-_config = {"subProcess": True}
+_config = {
+    "qt": "auto",
+    "subProcess": True,
+}
+
+_config_valid_values = {
+    # If property is not listed here, any value is considered valid, so long as
+    # its type matches that of the default value in _config.
+    "qt": ["auto", "none", "pyside", "pyside2", "pyqt4", "pyqt5"],
+}
 
 # This must be a global to prevent it from being garbage collected and triggering
 # https://bugs.python.org/issue37380.
@@ -85,6 +94,9 @@ def configure(properties, **kwargs):
         expected_type = type(_config[k])
         if type(v) is not expected_type:
             raise ValueError(fmt("{0!r} must be a {1}", k, expected_type.__name__))
+        valid_values = _config_valid_values.get(k)
+        if (valid_values is not None) and (v not in valid_values):
+            raise ValueError(fmt("{0!r} must be one of: {1!r}", k, valid_values))
         _config[k] = v
 
 
@@ -109,6 +121,10 @@ def debug(address, **kwargs):
         log.debug("{0}({1!r}, **{2!r})", func.__name__, address, kwargs)
         log.info("Initial debug configuration: {0!j}", _config)
 
+        qt_mode = _config.get("qt", "auto")
+        if qt_mode != "none":
+            pydevd.enable_qt_support(qt_mode)
+
         settrace_kwargs = {
             "suspend": False,
             "patch_multiprocessing": _config.get("subProcess", True),

src/debugpy/server/cli.py

@@ -50,7 +50,7 @@ class Options(object):
 
 
 options = Options()
-options.config = {"subProcess": True}
+options.config = {"qt": "auto", "subProcess": True}
 
 
 def in_range(parser, start, stop):