Component Failing : io.appium.uiautomator2.server.test/androidx.test.runner.AndroidJUnitRunner [crashed]

[VenkateshSeenivasan]

AT the time of test execution the uiautomator2 keeps on crashing on the android build [flutter] generated though Jenkins [using shell command] and installed in the emulator and this behaviour is not noticed in the build directly run on the emulator and the above behaviour noticed in the Android 14 and 15 and In Android 13 works as expected.

crash_log_of_UIAutomator2.log

[KazuCocoa]

Was the Flutter app a release build? If not, could it occur with a release build also? (if flutter debug build affected the uia2 process)
Can you share the full appium server log as well?

[VenkateshSeenivasan]

Hi @KazuCocoa , Please find the appium server log for the same.

appium-server.log

FYI : When ever the the uia2 crashed, we see that log
Connection to ws://127.0.0.1:37889/58x-DH4QS_g=/ws closed
in the appium server log.

Could you please have a look and suggest how to avoid this or correct us If we were doing something wrong unknowingly !!!!/.

[KazuCocoa]

I guess you referenced around:

2025-05-26 07:47:11:169 [HTTP] --> GET /wd/hub/status {}
2025-05-26 07:47:11:169 [AppiumDriver@adec] Calling AppiumDriver.getStatus() with args: []
2025-05-26 07:47:11:169 [AppiumDriver@adec] Responding to client with driver.getStatus() result: {"ready":true,"message":"The server is ready to accept new connections","build":{"version":"2.18.0"}}
2025-05-26 07:47:11:169 [HTTP] <-- GET /wd/hub/status 200 0 ms - 111 
2025-05-26 07:47:11:483 [47de46ea][FlutterDriver@2258] Connection to ws://127.0.0.1:37889/58x-DH4QS_g=/ws closed
2025-05-26 07:47:11:671 [HTTP] --> GET /wd/hub/status {}
2025-05-26 07:47:11:671 [AppiumDriver@adec] Calling AppiumDriver.getStatus() with args: []
2025-05-26 07:47:11:671 [AppiumDriver@adec] Responding to client with driver.getStatus() result: {"ready":true,"message":"The server is ready to accept new connections","build":{"version":"2.18.0"}}
2025-05-26 07:47:11:672 [HTTP] <-- GET /wd/hub/status 200 0 ms - 111 
2025-05-26 07:47:11:691 [Appium] Received SIGTERM - shutting down
2025-05-26 07:47:11:692 [AppiumDriver@adec] Cleaning up 1 active session
2025-05-26 07:47:11:692 [AppiumDriver@adec] Ending session, cause was 'The process has received SIGTERM signal'
2025-05-26 07:47:11:692 [AppiumDriver@adec] Removing session 'b99ca048-067f-439f-b2b3-ec0e8dd961c2' from our master session list
2025-05-26 07:47:11:693 [FlutterDriver@2258] Deleting Flutter Driver session
2025-05-26 07:47:11:693 [FlutterDriver@2258] Cleanup the port forward
2025-05-26 07:47:11:693 [ADB] Removing forwarded port socket connection: 37889 
2025-05-26 07:47:11:693 [ADB] Running '/Users/hoffensoft/Library/Android/sdk/platform-tools/adb -P 5037 -s emulator-5554 forward --remove tcp:37889'
2025-05-26 07:47:11:710 [FlutterDriver@2258] Deleting the proxy driver session.
2025-05-26 07:47:11:710 �[38;5;-170m[AndroidUiautomator2Driver@b146] Deleting UiAutomator2 session
2025-05-26 07:47:11:711 �[38;5;-170m[AndroidUiautomator2Driver@b146] Deleting UiAutomator2 server session
2025-05-26 07:47:11:711 �[38;5;-170m[AndroidUiautomator2Driver@b146] Proxying [DELETE /] to [DELETE http://127.0.0.1:8200/session/dd7debbd-9b9d-485d-83ea-3f4d41e974ad] with no body
2025-05-26 07:47:11:718 �[38;5;-170m[AndroidUiautomator2Driver@b146] Got response with status 200: {"sessionId":"dd7debbd-9b9d-485d-83ea-3f4d41e974ad","value":null}
2025-05-26 07:47:11:718 [ADB] Getting IDs of all 'io.appium.uiautomator2.server' processes
2025-05-26 07:47:11:718 [ADB] Running '/Users/hoffensoft/Library/Android/sdk/platform-tools/adb -P 5037 -s emulator-5554 shell 'pgrep --help; echo $?''
2025-05-26 07:47:11:771 [ADB] Running '/Users/hoffensoft/Library/Android/sdk/platform-tools/adb -P 5037 -s emulator-5554 shell pgrep -f \(\[\[:blank:\]\]\|\^\)io\.appium\.uiautomator2\.server\(:\[a-zA-Z0-9_-\]\+\)\?\(\[\[:blank:\]\]\|\$\)'
2025-05-26 07:47:11:787 [47de46ea]�[38;5;-170m[AndroidUiautomator2Driver@b146] [Instrumentation] io.appium.uiautomator2.server.test.AppiumUiAutomator2Server:.
2025-05-26 07:47:11:787 [47de46ea]�[38;5;-170m[AndroidUiautomator2Driver@b146] [Instrumentation] 
2025-05-26 07:47:11:787 [47de46ea]�[38;5;-170m[AndroidUiautomator2Driver@b146] [Instrumentation] Time: 532.273
2025-05-26 07:47:11:787 [47de46ea]�[38;5;-170m[AndroidUiautomator2Driver@b146] [Instrumentation] 
2025-05-26 07:47:11:787 [47de46ea]�[38;5;-170m[AndroidUiautomator2Driver@b146] [Instrumentation] OK (1 test)
2025-05-26 07:47:11:787 [47de46ea]�[38;5;-170m[AndroidUiautomator2Driver@b146] [Instrumentation] 
2025-05-26 07:47:11:787 [47de46ea]�[38;5;-170m[AndroidUiautomator2Driver@b146] [Instrumentation] 
2025-05-26 07:47:11:798 [47de46ea]�[38;5;-170m[AndroidUiautomator2Driver@b146] [Instrumentation] The process has exited with code 0, signal null

This log itself didn't have any possible "crash". The instrumentation process ended without any issues in terms of Appium logs. Usually the uia2 server crashes, you could see instrumentation process crash log in the appium log. The appium server ended by 2025-05-26 07:47:11:691 [Appium] Received SIGTERM - shutting down. It means the appium process got SIGTERM signal from outside Appium server process. Somewhere on your env sent the signal to Appium server process.

Connection to ws://127.0.0.1:37889/58x-DH4QS_g=/ws closed was not an error. https://github.com/appium/appium-flutter-driver/blob/b3e44d0b0e60e90937d02e7b875824c8e3ac2eeb/driver/lib/sessions/observatory.ts#L52 was one of normal session end.

So, basically by the log, Appium server side didn't have any issues, but somewhere your env sent SIGTERM signal to Appium server (and it closed the session)

[VenkateshSeenivasan]

@KazuCocoa
we were monitoring the appium server logs and when the socket connection gets closed in the middle of the test execution, we stop the server.
below is the code snippet included in the test suite to avoid the waiting time in the CI/CD pipe line.

But before this SIGTERM - shutting down signal,

the web socket gets closed based on onErrorListener --> And how to get those error received for this session.
07:47:11:483 [47de46ea][FlutterDriver@2258] Connection to ws://127.0.0.1:37889/58x-DH4QS_g=/ws closed

 socket.on(`error`, onErrorListener);
    // Add a 'close' event handler for the client socket
    socket.on(`close`, () => {
      this.log.info(`Connection to ${dartObservatoryURL} closed`);
      // @todo do we need to set this.socket = null?

code snippet included in the test suite to avoid the waiting time in the CI/CD pipe line.

public static void monitorLogFileAndStopService(File logFile) throws Exception {
		try (RandomAccessFile reader = new RandomAccessFile(logFile, "r")) {
			long filePointer = reader.length(); // Start at end of file
			while (service.isRunning()) {
				long fileLength = logFile.length();
				if (fileLength < filePointer) {
					// Log file was reset or rotated
					filePointer = fileLength;
				} else if (fileLength > filePointer) {
					reader.seek(filePointer);
					String line;
					while ((line = reader.readLine()) != null) {
						String decodedLine = new String(line.getBytes("ISO-8859-1"), "UTF-8");
						if (decodedLine.contains("Connection to ws://") && decodedLine.contains("closed")) {
							System.out.println("Detected closed WebSocket connection. Stopping Appium server...");
							stopAppiumServer();
							stopLogcat();
							return;
						}
					}
					filePointer = reader.getFilePointer();
				}
				Thread.sleep(500);
			}
		} catch (IOException | InterruptedException e) {
			e.printStackTrace();
		}
	}

	public static void stopAppiumServer() {

		try {
			ProcessBuilder builder = new ProcessBuilder("killall", "node");
			Process process = builder.start();

			// Read any error messages
			BufferedReader reader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
			String line;
			while ((line = reader.readLine()) != null) {
				System.err.println(line);
			}

			process.waitFor();
			System.out.println("killall node executed successfully.");

		} catch (Exception e) {
			System.out.println("killall node not executed successfully.");
		}
		System.out.println("✅ Appium process killed.");

	}

[VenkateshSeenivasan]

@KazuCocoa , I would like to let you know this happened only on the build generated using the terminal command
flutter run lib/assets/flavors/{flavor}/main_{flavor}.dart --flavor {flavor} -d emulator-5554 --verbose
{flavor} --> will be replaced by the actual flavor name used in the development code base.
When I run the build on emulator using the android studio the web socket connection closure issue not appears.
we use the same test scripts for both the test execution scenarios.

[KazuCocoa]

his happened only on the build generated using the terminal command

I guess... then the disconnection is Dart VM related, which is out of control as Appium driver. As the driver, it connects a websocket connection provided by the App under test. Whether the websocket connection can be kept open depends on the app side.