Fix microsoft/ptvsd#2081: KeyError: 'PTVSD_LAUNCHER_PORT' happened when debug with "sudo"

Remove redundant use of sudo to spawn the launcher.

Add test for "sudo".

Author: int19h

src/debugpy/adapter/clients.py

@@ -248,16 +248,6 @@ def launch_request(self, request):
         if self.session.id != 1 or len(servers.connections()):
             raise request.cant_handle('"attach" expected')
 
-        sudo = request("sudo", json.default("Sudo" in self.session.debug_options))
-        if sudo:
-            if sys.platform == "win32":
-                raise request.cant_handle('"sudo":true is not supported on Windows.')
-        else:
-            if "Sudo" in self.session.debug_options:
-                raise request.isnt_valid(
-                    '"sudo":false and "debugOptions":["Sudo"] are mutually exclusive'
-                )
-
         # Launcher doesn't use the command line at all, but we pass the arguments so
         # that they show up in the terminal if we're using "runInTerminal".
         if "program" in request:
@@ -286,7 +276,7 @@ def launch_request(self, request):
         console_title = request("consoleTitle", json.default("Python Debug Console"))
 
         launchers.spawn_debuggee(
-            self.session, request, sudo, args, console, console_title
+            self.session, request, args, console, console_title
         )
 
     @_start_message_handler

src/debugpy/adapter/launchers.py

@@ -65,10 +65,8 @@ def terminate_debuggee(self):
                     pass
 
 
-def spawn_debuggee(session, start_request, sudo, args, console, console_title):
-    cmdline = ["sudo"] if sudo else []
-    cmdline += [sys.executable, os.path.dirname(launcher.__file__)]
-    cmdline += args
+def spawn_debuggee(session, start_request, args, console, console_title):
+    cmdline = [sys.executable, os.path.dirname(launcher.__file__)] + args
     env = {}
 
     arguments = dict(start_request.arguments)

tests/debugpy/test_run.py

@@ -7,11 +7,12 @@
 import os
 import pytest
 import re
+import sys
 import time
 
 import debugpy
 from debugpy.common import log, messaging
-from tests import debug, test_data
+from tests import debug, test_data, timeline
 from tests.debug import runners, targets
 from tests.patterns import some
 
@@ -90,6 +91,50 @@ def code_to_debug():
     assert "ok" in session.output("stdout")
 
 
+@pytest.mark.skipif(sys.platform == "win32", reason="sudo not available on Windows")
+@pytest.mark.parametrize("run", runners.all_launch)
+def test_sudo(pyfile, tmpdir, run, target):
+    # Since the test can't rely on sudo being allowed for the user, create a dummy
+    # sudo script that doesn't actually elevate, but sets an environment variable
+    # that can be checked in the debuggee.
+    sudo = tmpdir / "sudo"
+    sudo.write(
+        """#!/bin/sh
+        exec env DEBUGPY_SUDO=1 "$@"
+        """
+    )
+    os.chmod(sudo.strpath, 0o777)
+
+    @pyfile
+    def code_to_debug():
+        import os
+
+        import debuggee
+        from debuggee import backchannel
+
+        debuggee.setup()
+        backchannel.send(os.getenv("DEBUGPY_SUDO", "0"))
+
+    with debug.Session() as session:
+        session.config["sudo"] = True
+        session.config.env["PATH"] = tmpdir.strpath + ":" + os.environ["PATH"]
+
+        backchannel = session.open_backchannel()
+        with run(session, target(code_to_debug)):
+            pass
+
+        # The "runInTerminal" request sent by the adapter to spawn the launcher,
+        # if any, shouldn't be using sudo.
+        assert all(
+            "sudo" not in req.arguments["args"]
+            for req in session.all_occurrences_of(timeline.Request("runInTerminal"))
+        )
+
+        # The launcher, however, should use our dummy sudo to spawn the debuggee,
+        # and the debuggee should report the environment variable accordingly.
+        assert backchannel.receive() == "1"
+
+
 @pytest.mark.parametrize(
     # Can't test "internalConsole", because we don't have debuggee stdin to press the key.
     "run",