Unable to debug Xamarin Forms Android project in VS 17.3 Preview 3 with Fast Deploy disabled

[BlueRaja]

Android application type

Android for .NET (net6.0-android, etc.)

Affected platform version

VS 17.3 Preview 3

Description

After updating to VS 17.3 Preview 3, debugging my Xamarin Forms Android project in the Android emulator doesn't work. The emulator opens, the project is successfully deployed, but then the app opens and immediately closes.

The deploy succeeds, so the app can still be run on the emulator by clicking the app-icon. But, the debugger will not be attached, making it extremely difficult to debug anything.

Downgrading to VS 17.2 (where debugging Android emulation works) is not an option for me, because Xamarin iOS is broken in that version 🤦

Steps to Reproduce

1. Open any Xamarin Forms Android project
2. In Project Properties --> Android Options, make sure "Fast Deploy" is disabled
3. Attempt to debug

Did you find any workaround?

Enable "Fast Deploy".

I previously had disabled it because of issues that I don't remember. I have no idea if those have been fixed.

Relevant log output

Debug Output:

Terminated existing process
> am start -a "android.intent.action.MAIN" -c "android.intent.category.LAUNCHER" -n "com.Ringotan/crc64da92c648e6bdeb4e.MainActivity"
> Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.Ringotan/crc64da92c648e6bdeb4e.MainActivity }

Could not connect to the debugger.

Xamarin Diagnostics Output

[I:]:                     Got new device list from adb with 1 devices
[I:]:                     Got new device list from adb with 1 devices
[I:]:                     Got new device list from adb with 1 devices
[E:]:                     Index (zero based) must be greater than or equal to zero and less than the size of the argument list.
System.FormatException: Index (zero based) must be greater than or equal to zero and less than the size of the argument list.
   at System.Text.StringBuilder.AppendFormatHelper(IFormatProvider provider, String format, ParamsArray args)
   at System.String.FormatHelper(IFormatProvider provider, String format, ParamsArray args)
   at System.String.Format(String format, Object[] args)
   at Mono.AndroidTools.AndroidLogger.LogError(String task, String format, Object[] args) in D:\a\_work\1\s\External\androidtools\Mono.AndroidTools\AndroidLogger.cs:line 63
   at Mono.AndroidTools.AndroidDevice.<>c__DisplayClass118_0.<RunShellCommandAsync>b__0() in D:\a\_work\1\s\External\androidtools\Mono.AndroidTools\AndroidDevice.cs:line 1012

[BlueRaja]

I found a workaround - enable "Fast Deploy" in Project Properties --> Android Options. I'll update the ticket accordingly

[mstefarov]

I think I might be running into the same issue, with VS 17.3.3. Trying to debug in an emulator and seeing this in "Xamarin Diagnostics" output:

[E:]:                     Index (zero based) must be greater than or equal to zero and less than the size of the argument list.
System.FormatException: Index (zero based) must be greater than or equal to zero and less than the size of the argument list.
   at System.Text.StringBuilder.AppendFormatHelper(IFormatProvider provider, String format, ParamsArray args)
   at System.String.FormatHelper(IFormatProvider provider, String format, ParamsArray args)
   at System.String.Format(String format, Object[] args)
   at Mono.AndroidTools.AndroidLogger.LogError(String task, String format, Object[] args) in D:\a\_work\1\s\External\androidtools\Mono.AndroidTools\AndroidLogger.cs:line 63
   at Mono.AndroidTools.AndroidDevice.<>c__DisplayClass118_0.<RunShellCommandAsync>b__0() in D:\a\_work\1\s\External\androidtools\Mono.AndroidTools\AndroidDevice.cs:line 1012

And this in "Debug" output:

[time.tests.mau] * Assertion: should not be reached at /__w/1/s/src/mono/mono/mini/mini-exceptions.c:456
[libc] Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 19241 (Debugger agent), pid 19216 (time.tests.maui)
The connection with the debugger has been lost. The target application may have exited.
Mono.Debugger.Soft.VMDisconnectedException: Exception of type 'Mono.Debugger.Soft.VMDisconnectedException' was thrown.
   at Mono.Debugger.Soft.ThreadMirror.GetFrames() in D:\a\_work\1\s\External\debugger-libs\Mono.Debugger.Soft\Mono.Debugger.Soft\ThreadMirror.cs:line 28
   at Mono.Debugging.Soft.SoftDebuggerSession.ExceptionInUserCode(ExceptionEvent ev) in D:\a\_work\1\s\External\debugger-libs\Mono.Debugging.Soft\SoftDebuggerSession.cs:line 2049
   at Mono.Debugging.Soft.SoftDebuggerSession.HandleBreakEventSet(Event[] es, Boolean dequeuing) in D:\a\_work\1\s\External\debugger-libs\Mono.Debugging.Soft\SoftDebuggerSession.cs:line 2097
   at Mono.Debugging.Soft.SoftDebuggerSession.EventHandler() in D:\a\_work\1\s\External\debugger-libs\Mono.Debugging.Soft\SoftDebuggerSession.cs:line 1794

For me, enabling "Fast deploy" did not fix the issue though.

[jpobst]

This appears to have been fixed here: https://github.com/xamarin/androidtools/pull/365.