From mobile apps to microservices, from small startups to big enterprises, Gradle helps teams build, automate and deliver better software, faster.

Gradle Community

Untitled.kt

What do you mean with "this" that you did not create?

The cause for the problems?
Then yes, you did

```val available = tasks.register("tests available") {
  val ss = sourceSets;```

You capture `sourceSets` and use it at runtime.
So it is tried to be serialized into configuration cache.
And that is not supported

I feel like there's a reason I did that, but I don't recall why

also possible it's copy pasta of someone elses code for fixing the problem that gradle doesn't blow up if it doesn't find tests and provides no facility for that behavior

```val available = tasks.register("tests available") {
    val java: Provider&lt;FileCollection&gt; = sourceSets.test.map { it.java }
    doLast {
        if (java.get().isEmpty) throw RuntimeException("no tests found")
    }
}```

:thinking_face:
```&gt; Task :app:tests available FAILED
Caching disabled for task ':app:tests available' because:
  Gradle would require more information to cache this task
Task ':app:tests available' is not up-to-date because:
  Task has not declared any outputs despite executing actions.```


Why did it fail? You didn't paste any error

```FAILURE: Build completed with 2 failures.

1: Task failed with an exception.
-----------
* What went wrong:
Execution failed for task ':app:tests available'.
&gt; class org.gradle.api.internal.file.collections.FileTreeAdapter cannot be cast to class org.gradle.api.file.SourceDirectorySet (org.gradle.api.internal.file.collections.FileTreeAdapter and org.gradle.api.file.SourceDirectorySet are in unnamed module of loader org.gradle.internal.classloader.VisitableURLClassLoader @1b701da1)```

oh, it's because I removed the `Provider&lt;` type...