From c14b298cb91ceb12ecb0aeac5a8264b6f0f3f7d6 Mon Sep 17 00:00:00 2001
From: Ivan Kravets <me@ikravets.com>
Date: Fri, 19 Mar 2021 15:55:42 +0200
Subject: [PATCH] Fixed an issue with silent hanging when a custom debug server
 is not found // Resolve #3756

---
 HISTORY.rst                        |  1 +
 platformio/commands/debug.py       | 14 ++++++++------
 platformio/debug/process/server.py |  7 +++----
 3 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/HISTORY.rst b/HISTORY.rst
index 59edd6de..141fba3e 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -16,6 +16,7 @@ PlatformIO Core 5
   - Boosted `PlatformIO Debugging <https://docs.platformio.org/page/plus/debugging.html>`__  performance thanks to migrating the codebase to the pure Python 3 Asynchronous I/O stack
   - Support debugging on Windows using Windows CMD/CLI (`pio debug <https://docs.platformio.org/page/core/userguide/cmd_debug.html>`__) (`issue #3793 <https://github.com/platformio/platformio-core/issues/3793>`_)
   - Configure a custom pattern to determine when debugging server is started with a new `debug_server_ready_pattern <https://docs.platformio.org/page/projectconf/section_env_debug.html#debug-server-ready-pattern>`__ option
+  - Fixed an issue with silent hanging when a custom debug server is not found (`issue #3756 <https://github.com/platformio/platformio-core/issues/3756>`_)
 
 5.1.1 (2021-03-17)
 ~~~~~~~~~~~~~~~~~~
diff --git a/platformio/commands/debug.py b/platformio/commands/debug.py
index c2df11ee..3f468de9 100644
--- a/platformio/commands/debug.py
+++ b/platformio/commands/debug.py
@@ -155,11 +155,13 @@ def cli(ctx, project_dir, project_conf, environment, verbose, interface, __unpro
     asyncio.set_event_loop(loop)
     client = GDBClientProcess(project_dir, debug_config)
     coro = client.run(__unprocessed)
-    loop.run_until_complete(coro)
-    del client
-    if IS_WINDOWS:
-        # an issue with asyncio executor and STIDIN, it cannot be closed gracefully
-        proc.force_exit()
-    loop.close()
+    try:
+        loop.run_until_complete(coro)
+        if IS_WINDOWS:
+            # an issue with asyncio executor and STIDIN, it cannot be closed gracefully
+            proc.force_exit()
+    finally:
+        del client
+        loop.close()
 
     return True
diff --git a/platformio/debug/process/server.py b/platformio/debug/process/server.py
index d1fe5e7d..1fb08f4d 100644
--- a/platformio/debug/process/server.py
+++ b/platformio/debug/process/server.py
@@ -51,10 +51,9 @@ class DebugServerProcess(DebugBaseProcess):
             server_executable = where_is_program(server_executable)
         if not os.path.isfile(server_executable):
             raise DebugInvalidOptionsError(
-                "\nCould not launch Debug Server '%s'. Please check that it "
-                "is installed and is included in a system PATH\n\n"
-                "See documentation:\n"
-                "https://docs.platformio.org/page/plus/debugging.html\n"
+                "Could not launch Debug Server '%s'. Please check that it "
+                "is installed and is included in a system PATH\n"
+                "See https://docs.platformio.org/page/plus/debugging.html"
                 % server_executable
             )