# Trying to add task dependency but it claims the task doesn't exist

**URL:** <https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595>\
**Category:** Help/Discuss\
**Created:** [May 31, 2024, 7:38pm UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595 "2024-05-31T19:38:38Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![mjparme](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@mjparme](https://discuss.gradle.org/u/mjparme)\
**Post date:** [May 31, 2024, 7:38pm UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/1 "2024-05-31T19:38:38Z")

</div>

I am trying to generate code with an OpenAPI plugin, the plugin adds a task called `processSpring`. For some reason gradle believes that tasks depends on `generateEffectiveLombokConfig`.

```plaintext
Reason: Task ':foo:processSpring' uses this output of task ':foo:generateEffectiveLombokConfig' without > declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending > on what order the tasks are executed.

   > Possible solutions:
     > 1. Declare task ':foo:generateEffectiveLombokConfig' as an input of ':foo:processSpring'.
      > 2. Declare an explicit dependency on ':foo:generateEffectiveLombokConfig' from ':foo:processSpring' using Task#dependsOn.
      > 3. Declare an explicit dependency on ':foo:generateEffectiveLombokConfig' from ':foo:processSpring' using Task#mustRunAfter.

```

In an attempt to appease Gradle I add:

```groovy
 tasks.named('processSpring') { task ->
    task.dependsOn('generateEffectiveLombokConfig')
}

```

But then I get the error:

```plaintext
A problem occurred evaluating project ':foo'.
Task with name 'processSpring' not found in project ':foo'.

```

How can processSpring not exist in the project when the first error specifically telling me there is a processSpring task in the project that is depending on `generateEffectiveLombokConfig`?

And not only that but I have this line in the build file before this:

```groovy
compileJava.dependsOn ('processSpring')

```

and it doesn’t complain about that at all.

Also the output of `./gradlew tasks -all` shows the processSpring task:

```plaintext
Openapi processor tasks
foo:processSpring - process openapi with openapi-processor-spring

```

---

<div class="post-metadata">

**Author:** ![Vampire](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/vampire/32/9082_2.png) [@Vampire](https://discuss.gradle.org/u/Vampire)\
**Post date:** [June 1, 2024, 10:53am UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/2 "2024-06-01T10:53:52Z")

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> For some reason gradle believes that tasks depends on generateEffectiveLombokConfig.

The “some reason” is, that the inputs of `processSpring` contain any of the outputs of `generateEffectiveLombokConfig` wihtout the tasks having any declared relation.

But the advices you get from Gradle are imho really bad.  
They are just symptom treatment.  
They do not fix the real problem and just move the problem aside to a later time where it is even harder to reproduce find and fix.  
You should never have any explicit `dependsOn` (except with a lifecycle task on the left-hand side), but instead wire task outputs to task inputs properly so that you get the necessary task dependency automatically.  
How the correct solution is in your case is hard to tell without having a look at the actual build and how it is configured.

> How can processSpring not exist in the project when the first error specifically telling me there is a processSpring task in the project that is depending on generateEffectiveLombokConfig?

What it tells you is, that the task does not exist **yet** when you call the `named` method. It is added in a later stage. If you really want to go the bad way of adding an explicit dependency, use something like `tasks.named { it == "processSpring" }.configureEach { dependsOn(...) }`, this will also match tasks that are added after you called it.

> and it doesn’t complain about that at all.

Because you do not depend on a task, you depend on a String representation of a task, and this String is resolved to the actual task very late when the task is finally there already.

---

<div class="post-metadata">

**Author:** ![mjparme](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@mjparme](https://discuss.gradle.org/u/mjparme)\
**Post date:** [June 3, 2024, 2:52pm UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/3 "2024-06-03T14:52:48Z")

</div>

> [@Vampire](#):
>
> but instead wire task outputs to task inputs properly so that you get the necessary task dependency automatically.

Unfortunately the two tasks are in different 3rd party plugins and as far as I can tell I have no control over how the task inputs are declared.

> [@Vampire](#):
>
> What it tells you is, that the task does not exist **yet** when you call the `named` method.

After messing with it more after making this post I finally decided it was a race condition and the tasks were being added later and weren’t there when that part of the configuration phase was running. So it is nice to have confirmation that I was on the right track with that.

> [@Vampire](#):
>
> If you really want to go the bad way of adding an explicit dependency,

Unless I am missing something and there is a way for me to declare task inputs for a task in a 3rd party plugin it looks like I will just have to do this workaround. Thanks for the workaround, I will give it a go.

---

<div class="post-metadata">

**Author:** ![Vampire](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/vampire/32/9082_2.png) [@Vampire](https://discuss.gradle.org/u/Vampire)\
**Post date:** [June 3, 2024, 3:03pm UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/4 "2024-06-03T15:03:09Z")

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> Unfortunately the two tasks are in different 3rd party plugins and as far as I can tell I have no control over how the task inputs are declared.

You usually can configure any 3rd party plugin’s task however you need it.  
But as I said, I know too little about your build to tell concretely what to change.

---

<div class="post-metadata">

**Author:** ![johanE](https://avatars.discourse-cdn.com/v4/letter/j/4bbf92/32.png) [@johanE](https://discuss.gradle.org/u/johanE)\
**Post date:** [June 5, 2024, 9:57am UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/5 "2024-06-05T09:57:46Z")

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I had the a similar experience. In my case I needed to disable tasks introduced by plugins and all DataBaseUpgradTasks (There is easier ways to disable all tasks of certain type.)

I found something on stackexchange that I can’t find now. But I have the solution. It is about creating a listener that waits for all projects to be configured before calling a closure. I’ll share a snippet from my build.gradle file. The snippet can be used to introduce task dependencies instead of disable them.

```gradle
static void whenAllProjectsEvaluated(Project rootProject, Closure action) {
    final java.util.concurrent.atomic.AtomicInteger counter = new java.util.concurrent.atomic.AtomicInteger()
    final int allProjectsCount = rootProject.getAllprojects().size()
    rootProject.allprojects { p ->
        p.afterEvaluate {
            final int currentEvaluatedCount = counter.incrementAndGet()
            rootProject.logger.lifecycle("${p.name} - afterEvaluate (${currentEvaluatedCount}/$allProjectsCount")
            if (currentEvaluatedCount == allProjectsCount) {
                action.call()
            }
        }
    }
}
whenAllProjectsEvaluated(project) {
    project['updateAndConfigure'].enabled = false
    project['upgradeConfigFiles'].enabled = false
    project['copyDBFolder'].enabled = false

    project.subprojects.each{
        it.tasks.each{
            if (it instanceof com.iipax.gradle.tasks.DatabaseUpgradeTask)
                it.enabled = false
        }
   }
}

```

---

<div class="post-metadata">

**Author:** ![Vampire](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/vampire/32/9082_2.png) [@Vampire](https://discuss.gradle.org/u/Vampire)\
**Post date:** [June 5, 2024, 10:21am UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/6 "2024-06-05T10:21:44Z")

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That is stacking up various highly discouraged bad-practices on top of each other.  
You should really not do something like that.  
Especially when there are so much easier and more reliable ways like `tasks.withType<...>.configureEach { ... }` and `tasks.named { ... }.configureEach { ... }` if you really do such manipulation as already said above. 😉

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<div class="post-metadata">

**Author:** ![johanE](https://avatars.discourse-cdn.com/v4/letter/j/4bbf92/32.png) [@johanE](https://discuss.gradle.org/u/johanE)\
**Post date:** [June 5, 2024, 10:53am UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/7 "2024-06-05T10:53:12Z")

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Might be, but when you can’t get hold of tasks before all projects are evaluated. Then you need to to something that works.

---

<div class="post-metadata">

**Author:** ![Vampire](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/vampire/32/9082_2.png) [@Vampire](https://discuss.gradle.org/u/Vampire)\
**Post date:** [June 5, 2024, 11:28am UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/8 "2024-06-05T11:28:07Z")

</div>

`tasks.withType` and `tasks.named { ... }` work on all tasks, be they registered before your code runs or after.

---

<div class="post-metadata">

**Author:** ![johanE](https://avatars.discourse-cdn.com/v4/letter/j/4bbf92/32.png) [@johanE](https://discuss.gradle.org/u/johanE)\
**Post date:** [June 5, 2024, 1:13pm UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/9 "2024-06-05T13:13:15Z")

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Maybe this is a gradle version issue and tasks.named() works better in newer versions. named() isn’t even available on the version I was forced to use. getByName says that the task isn’t available either. But the solution that you say is full of bad practice works.

I was on 4.8 😊

---

<div class="post-metadata">

**Author:** ![Vampire](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/vampire/32/9082_2.png) [@Vampire](https://discuss.gradle.org/u/Vampire)\
**Post date:** [June 5, 2024, 1:15pm UTC](https://discuss.gradle.org/t/trying-to-add-task-dependency-but-it-claims-the-task-doesnt-exist/48595/10 "2024-06-05T13:15:12Z")

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Yes, `tasks.named { ... }` is relatively new.  
`tasks.named(...)` does not work like that and requires that the task is already there.  
But on older versions you can use `tasks.matching { it.name == ... }.configureEach { ... }`.