Build fails when using WorkManager and D8

[tranb3r]

Xamarin.Android Version (eg: 6.0):

9.3.0.14

Operating System & Version (eg: Mac OSX 10.11):

Windows 10 1809

Support Libraries Version (eg: 23.3.0):

28.0.0.1

Describe your Issue:

Enabling D8 when using Workmanager causes Build to fail.

Steps to Reproduce (with link to sample solution if possible):

Add Xamarin.Android.Arch.Work.Runtime NuGet package and use the WorkManager to enqueue some worker.
Enable D8 in android csproj (<AndroidDexTool>d8</AndroidDexTool>)
R8 or Proguard is NOT enabled.
Build fails.

You can use this sample to reproduce : https://github.com/JonDouglas/WorkManagerSample
When enabling D8, build fails.

Include any relevant Exception Stack traces, build logs, adb logs:

R8 : warning : Missing class: android.arch.paging.PositionalDataSource
R8 : error : Compilation can't be completed because some library classes are missing.

[sgong-pdftron]

Any update on this issue? I am having similar situation and trying to bind a library that is using Room, the exact same error (Missing class: android.arch.paging.PositionalDataSource) is showing up as well. And I cannot seem to find a package that contains this class. Thanks.

[sgong-pdftron]

Update: manually including the android.paging common jar (tested with common-1.0.1.jar) as EmbeddedJar in the binding library will create a successful build.

[tranb3r]

Xamarin.Firebase.JobDispatcher nuget has been removed from nuget.org.
So I guess WorkManager is now the only way to schedule a job properly.
Anybody working on a fix for this issue ? It's really becoming a blocker for me...

[tranb3r]

I've opened this ticket more than 2 months ago, and so far it's been totally ignored.
Is this component maintained ?
How are we suppose to use it if build fails when using it ?!?

[riteshdubey86]

Has someone get the solution of this problem. We are getting this error in release mode.

[tranb3r]

I've managed to find a workaround (even if I do not fully understand why it works...):

1. Add this to your proguard.cfg

-keep public class android.arch.lifecycle.ProcessLifecycleOwnerInitializer { *; }
-keep public class androidx.work.impl.** { *; }
-dontwarn android.arch.paging.PositionalDataSource

2. Add this to your LinkerConfig.xml

<assembly fullname="Xamarin.Android.Arch.Work.Runtime">
  <type fullname="*" />
</assembly>

@riteshdubey86, hope this helps!

[furystormss]

Same problem here. The workaround provided by @tranb3r isn't working for me.
"Compilation can't be completed because some library classes are missing."

"Proguard configuration file 'C:\Users\user.nuget\packages\xamarin.android.arch.persistence.room.runtime\1.1.1.1\build....\proguard\proguard.txt' was not found.'"

"Proguard configuration file 'C:\Users\user.nuget\packages\xamarin.android.arch.work.runtime\1.0.0\build....\proguard\proguard.txt'"

"Missing class: android.arch.paging.PositionalDataSource"

using NuGet Xamarin.Android.Arch.Work.Runtime

[diegostamigni]

@martijn-nap just add -keep public class android.arch.paging.** { *; } to your proguard cfg

[furystormss]

@martijn-nap just add -keep public class android.arch.paging.** { *; } to your proguard cfg

That does not (re)solve anything... Same errors still happen

[diegostamigni]

That's what I have and works fine to me @martijn-nap. Try adding the notwarn too, such that you end up with:

-keep class android.arch.paging.** { *; } 
-dontwarn android.arch.paging.**

[furystormss]

Removes the warning (ofcourse) but makes the App startup and instantly crashes. Also adds a lot of other errors...

[diegostamigni]

Removes the warning (ofcourse) but makes the App startup and instantly crashes. Also adds a lot of other errors...

It might be for other reasons tho, following is my proguard cfg I use to one of my projects where I have workers: Proguard.txt

Try it and let us know @martijn-nap

[furystormss]

Works with your file! Going to narrow it down now to see what the missing rule is.

EDIT: thanks for the help! Problem was that -keep class androidx.work.impl.** { *; } was missing.

[diegostamigni]

Yeah, you're missing something else in your proguard cfg. Afaik it should tell you if you check carefully your build log tho. After all, I've been populating my cfg from there (+ the standard Xamarin suggested ones)

[3akat]

@martijn-nap @diegostamigni
Guys, can you please create a demo app where the issue is fixed with your workaround? I've tried but no success. Would really appreciate!