title: unable to start app from Appium Desktop app. Got an error during apksigner execution
body: <p>An unknown server-side error occurred while processing the command. Original error: Could not sign with default certificate. Original error spawn ENOTDIR</p>
  
  <p>I am trying to start an android app using Appium Desktop app. Appium server shows the following error log;</p>
  
  <blockquote>
    <p>Starting '/home/santoshpc/Android/Sdk/build-tools/28.0.3/apksigner'
    with args
    '["sign","--key","/tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-adb/keys/testkey.pk8","--cert","/tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-adb/keys/testkey.x509.pem","/tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-uiautomator2-server/apks/appium-uiautomator2-server-debug-androidTest.apk"]'
    [ADB] Got an error during apksigner execution: Command
    '/home/santoshpc/Android/Sdk/build-tools/28.0.3/apksigner sign --key
    /tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-adb/keys/testkey.pk8
    --cert /tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-adb/keys/testkey.x509.pem
    /tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-uiautomator2-server/apks/appium-uiautomator2-server-debug-androidTest.apk'
    exited with code 1 [ADB] apksigner stderr: Exception in thread "main"
    java.nio.file.FileSystemException:
    /tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-uiautomator2-server/apks/appium-uiautomator2-server-debug-androidTest.apk:
    Read-only file system [ADB]   at
    sun.nio.fs.UnixException.translateToIOException(UnixException.java:91)
    [ADB]     at
    sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
    [ADB]     at
    sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
    [ADB]     at sun.nio.fs.UnixCopyFile.move(UnixCopyFile.java:447) [ADB]
      at
    sun.nio.fs.UnixFileSystemProvider.move(UnixFileSystemProvider.java:262)
    [ADB]     at java.nio.file.Files.move(Files.java:1395) [ADB]  at
    com.android.apksigner.ApkSignerTool.sign(ApkSignerTool.java:342) [ADB]
      at com.android.apksigner.ApkSignerTool.main(ApkSignerTool.java:89)
    [ADB]  [ADB] Cannot use apksigner tool for signing. Defaulting to
    sign.jar. Original error: Command
    '/home/santoshpc/Android/Sdk/build-tools/28.0.3/apksigner sign --key
    /tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-adb/keys/testkey.pk8
    --cert /tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-adb/keys/testkey.x509.pem
    /tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-uiautomator2-server/apks/appium-uiautomator2-server-debug-androidTest.apk'
    exited with code 1; StdErr: Exception in thread "main"
    java.nio.file.FileSystemException:
    /tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-uiautomator2-server/apks/appium-uiautomator2-server-debug-androidTest.apk:
    Read-only file system [ADB]   at
    sun.nio.fs.UnixException.translateToIOException(UnixException.java:91)
    [ADB]     at
    sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
    [ADB]     at
    sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
    [ADB]     at sun.nio.fs.UnixCopyFile.move(UnixCopyFile.java:447) [ADB]
      at
    sun.nio.fs.UnixFileSystemProvider.move(UnixFileSystemProvider.java:262)
    [ADB]     at java.nio.file.Files.move(Files.java:1395) [ADB]  at
    com.android.apksigner.ApkSignerTool.sign(ApkSignerTool.java:342) [ADB]
      at com.android.apksigner.ApkSignerTool.main(ApkSignerTool.java:89)
    [ADB]  [ADB] Resigning apk. [UiAutomator2] Deleting UiAutomator2
    session [UiAutomator2] Deleting UiAutomator2 server session [WD Proxy]
    Matched '/' to command name 'deleteSession' [UiAutomator2] Did not get
    confirmation UiAutomator2 deleteSession worked; Error was:
    UnknownError: An unknown server-side error occurred while processing
    the command. Original error: Trying to proxy a session command without
    session id [ADB] Running
    '/home/santoshpc/Android/Sdk/platform-tools/adb -P 5037 -s
    0123456789ABCDEF shell am force-stop eu.niko.smart.naswi.main'
    [Logcat] Stopping logcat capture [ADB] Removing forwarded port socket
    connection: 8200  [ADB] Running
    '/home/santoshpc/Android/Sdk/platform-tools/adb -P 5037 -s
    0123456789ABCDEF forward --remove tcp:8200' [UiAutomator2] Unable to
    remove port forward 'Error executing adbExec. Original error: 'Command
    '/home/santoshpc/Android/Sdk/platform-tools/adb -P 5037 -s
    0123456789ABCDEF forward --remove tcp:8200' exited with code 1';
    Stderr: 'error: listener 'tcp:8200' not found'; Code: '1''
    [BaseDriver] Event 'newSessionStarted' logged at 1552282079530
    (11:12:59 GMT+0545 (+0545)) [MJSONWP] Encountered internal error
    running command: Error: Could not sign with default certificate.
    Original error spawn ENOTDIR [MJSONWP]     at
    ADB.apkSigningMethods.signWithDefaultCert
    (/tmp/.mount_AppiumGDrtg1/resources/app/node_modules/appium/node_modules/appium-adb/lib/tools/apk-signing.js:124:13)
    [HTTP] &lt;-- POST /wd/hub/session 500 9847 ms - 206 [HTTP]  [HTTP] -->
    DELETE /wd/hub/session [HTTP] {} [HTTP] No route found. Setting
    content type to 'text/plain' [HTTP] &lt;-- DELETE /wd/hub/session 404 5
    ms - 57</p>
  </blockquote>
  
  <p>I have added following <strong>DesiredCapabilities</strong></p>
  
  <pre><code>{
    "noReset": true,
    "automationName": "uiautomator2",
    "appPackage": "myapp package name",
    "appActivity": "my app activity name",
    "deviceName": "My device",
    "platformName": "android"
  }
  </code></pre>
  
  <p>Appium Desktop version: 1.11.1
  OS - ubuntu</p>