Update test requirements

CONTRIBUTING.md

@@ -76,7 +76,7 @@ On Linux or macOS:
 
 ### Running tests without tox
 
-While tox is the recommended way to run the test suite, pytest can also be invoked directly from the root of the repository. This requires packages in tests/test_requirements.txt to be installed first.
+While tox is the recommended way to run the test suite, pytest can also be invoked directly from the root (src/debugpy) of the repository. This requires packages in tests/requirements.txt to be installed first.
 
 ## Using modified debugpy in Visual Studio Code
 To test integration between debugpy and Visual Studio Code, the latter can be directed to use a custom version of debugpy in lieu of the one bundled with the Python extension. This is done by specifying `"debugAdapterPath"` in `launch.json` - it must point at the root directory of the *package*, which is `src/debugpy` inside the repository:

src/debugpy/common/util.py

@@ -175,5 +175,5 @@ class WaitForTimeout():
     def __call__(self):
         if self._timeout is not None:
             time.sleep(self._timeout)
-        self.timed_out = True
+            self.timed_out = True
         self._func()

tests/requirements.txt

@@ -9,6 +9,7 @@ pytest-timeout
 
 importlib_metadata
 psutil
+untangle
 
 ## Used in Python code that is run/debugged by the tests: