# Why would a task, with several output directories, be considered up-to-date, if the directories don't exist yet?

**URL:** <https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463>\
**Category:** Old Forum Archive\
**Created:** [January 16, 2014, 1:50am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463 "2014-01-16T01:50:00Z")\
**Posts on this page:** 13\
**Page:** 1

<div class="post-metadata">

**Author:** ![Kevin\_Moody](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/kevin_moody/32/311_2.png) [@Kevin\_Moody](https://discuss.gradle.org/u/Kevin_Moody)\
**Post date:** [January 16, 2014, 1:50am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/1 "2014-01-16T01:50:00Z")

</div>

Given the following in a task:

```gradle
def testList = 'a'..'z'
        componentList = testList + testList + testList + testList + testList + testList
        outputs.files files(componentList.collect { "../../src/${it}/${winPlatform}" })
        println componentList.collect { "../../src/${it}/${winPlatform}" }
        println componentList.size()

```

The task executes as expected, because the ‘a’…‘z’ directories do not exist:

```gradle
...
../../src/x/win_x64, ../../src/y/win_x64, ../../src/z/win_x64]
156
:oldBuildscripts:makeTree
Executing on the following components - [a, b, c, ...

```

The reason why I tried so many of the above was due to the fact that my project has over a 130 real source component directories that are created by this task. However, when I specify the legitimate list of component directories, the task is always seen as up-to-date.

```gradle
[../../src/component1/win_x64, ../../src/component2/win_x64, ..., ../../src/component135/win_x64]
135
:oldBuildscripts:makeTree UP-TO-DATE

```

Even more puzzling is using a shorter list of components, such as the first 5, will execute the task:

```gradle
outputs.files files(componentList[1..5].collect { "../../src/${it}/${winPlatform}" })
        println componentList[1..5].collect { "../../src/${it}/${winPlatform}" }
        println componentList.size()

```

Output from the above:

```gradle
[../../src/component1/win_x64, ../../src/component2/win_x64, ../../src/component3/win_x64, ../../src/component4/win_x64, ../../s
rc/component5/win_x64]
135
:oldBuildscripts:makeTree
Executing on the following components - [...

```

Any ideas why this might be happening? This is the gradle wrapper with 1.9, executing on Windows 7 x64.

---

<div class="post-metadata">

**Author:** ![Peter\_Niederwieser](https://avatars.discourse-cdn.com/v4/letter/p/9f8e36/32.png) [@Peter\_Niederwieser](https://discuss.gradle.org/u/Peter_Niederwieser)\
**Post date:** [January 16, 2014, 2:22am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/2 "2014-01-16T02:22:00Z")

</div>

Are you saying that the task’s job is to create an empty directory structure?

---

<div class="post-metadata">

**Author:** ![Kevin\_Moody](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/kevin_moody/32/311_2.png) [@Kevin\_Moody](https://discuss.gradle.org/u/Kevin_Moody)\
**Post date:** [January 16, 2014, 2:33am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/3 "2014-01-16T02:33:00Z")

</div>

No. It’s a script that creates a sub-directory, for each component, which contain several files/symlinks. But, I can’t programmatically determine that entire list. So, my best approximation of a good task result is to verify that all of the output directories exist. Also, in order to clean the task, we just have to delete this same list.

---

<div class="post-metadata">

**Author:** ![Kevin\_Moody](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/kevin_moody/32/311_2.png) [@Kevin\_Moody](https://discuss.gradle.org/u/Kevin_Moody)\
**Post date:** [January 16, 2014, 2:35am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/4 "2014-01-16T02:35:00Z")

</div>

I haven’t verified this, yet, but, I think that I’m specifying an invalid value. I can only guess that this will cause the outputs to default to up-to-date. One of my strings may have a backslash in it (read in from an output stream). I’m trying to verify.

---

<div class="post-metadata">

**Author:** ![Peter\_Niederwieser](https://avatars.discourse-cdn.com/v4/letter/p/9f8e36/32.png) [@Peter\_Niederwieser](https://discuss.gradle.org/u/Peter_Niederwieser)\
**Post date:** [January 16, 2014, 2:36am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/5 "2014-01-16T02:36:00Z")

</div>

You may be looking for ‘outputs.dir’, rather than ‘outputs.file(s)’.

---

<div class="post-metadata">

**Author:** ![Kevin\_Moody](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/kevin_moody/32/311_2.png) [@Kevin\_Moody](https://discuss.gradle.org/u/Kevin_Moody)\
**Post date:** [January 16, 2014, 2:39am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/6 "2014-01-16T02:39:00Z")

</div>

I wasn’t sure if outputs.dir could take a FileCollection. But, I assumed that I had that wrong because of the behavior that I’m seeing. Perhaps, I should still be using outputs.dir. More importantly, I should be specifying the FileCollection, properly. 😉

---

<div class="post-metadata">

**Author:** ![Peter\_Niederwieser](https://avatars.discourse-cdn.com/v4/letter/p/9f8e36/32.png) [@Peter\_Niederwieser](https://discuss.gradle.org/u/Peter_Niederwieser)\
**Post date:** [January 16, 2014, 2:43am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/7 "2014-01-16T02:43:00Z")

</div>

You’ll have to call ‘outputs.dir’ once per top-level directory produced by the task, passing a ‘File’ or a ‘String’.

---

<div class="post-metadata">

**Author:** ![Kevin\_Moody](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/kevin_moody/32/311_2.png) [@Kevin\_Moody](https://discuss.gradle.org/u/Kevin_Moody)\
**Post date:** [January 16, 2014, 6:31am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/8 "2014-01-16T06:31:00Z")

</div>

I’m still at a loss. Thank you for the suggestion of using ‘outputs.dir’. That does seem to be what I want.

However, I can’t, for the life of me, figure out why this won’t work. I verified that I’m able to create valid ‘File’ objects, via the elements of my ‘componentList’. But, I can’t explain why the following doesn’t work, e.g. _it shouldn’t consider the task up-to-date_:

```gradle
build.gradle:
...
        componentList.each { outputs.dir file("../../src/${it}/${winPlatform}") }
...
output:
  $ gradlew makeTree
:oldBuildscripts:makeTree UP-TO-DATE
  BUILD SUCCESSFUL

```

But, this executes, properly:

```gradle
build.gradle:
...
        componentList[0..133].each { outputs.dir file("../../src/${it}/${winPlatform}") }
...
  output:
  $ gradlew makeTree
:oldBuildscripts:makeTree
Executing on the following components - [...]
...
build.gradle:
...
        componentList[1..134].each { outputs.dir file("../../src/${it}/${winPlatform}") }
...
  output:
  $ gradlew makeTree
:oldBuildscripts:makeTree
Executing on the following components - [...]
...

```

Is there something about groovy’s list iteration which I’m not getting here? I even tested specifying the full range, ‘componentList[0…134]’, but that considers the task up-to-date, too. This is bizarre.

So, to clarify, the task is not configured correctly when I pass the entire list range, but it is configured correctly when I pass a sub-list.

---

<div class="post-metadata">

**Author:** ![Peter\_Niederwieser](https://avatars.discourse-cdn.com/v4/letter/p/9f8e36/32.png) [@Peter\_Niederwieser](https://discuss.gradle.org/u/Peter_Niederwieser)\
**Post date:** [January 16, 2014, 6:37am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/9 "2014-01-16T06:37:00Z")

</div>

I’m afraid I can’t say from here what’s going on. Why do you think the task shouldn’t be up-to-date? Are you deleting or modifying some files contained in output directories between runs?

---

<div class="post-metadata">

**Author:** ![Kevin\_Moody](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/kevin_moody/32/311_2.png) [@Kevin\_Moody](https://discuss.gradle.org/u/Kevin_Moody)\
**Post date:** [January 16, 2014, 11:35am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/10 "2014-01-16T11:35:00Z")

</div>

Because the task never completed. It fails on the first component every time that it is run, due to an environment issue on my machine, which I’m also working on. E.g. only the first output directory exists.

---

<div class="post-metadata">

**Author:** ![Peter\_Niederwieser](https://avatars.discourse-cdn.com/v4/letter/p/9f8e36/32.png) [@Peter\_Niederwieser](https://discuss.gradle.org/u/Peter_Niederwieser)\
**Post date:** [January 16, 2014, 11:39am UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/11 "2014-01-16T11:39:00Z")

</div>

The only way I can think of to get up-to-date for a task that never completed is if its inputs are empty.

---

<div class="post-metadata">

**Author:** ![Kevin\_Moody](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/kevin_moody/32/311_2.png) [@Kevin\_Moody](https://discuss.gradle.org/u/Kevin_Moody)\
**Post date:** [January 16, 2014, 6:52pm UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/12 "2014-01-16T18:52:00Z")

</div>

I still think that the behavior is incredibly bizarre. Upon changing the outputs, it somehow sees the task as completed. Is it possible that it cached some early test that I did, when creating the task? Anyways, changing the inputs did the trick. It is now properly recognizing the task as out-of-date, with the complete list of the components specified as the outputs.dir(s). Thanks, Peter. I appreciate you pointing me in the right direction.

---

<div class="post-metadata">

**Author:** ![Peter\_Niederwieser](https://avatars.discourse-cdn.com/v4/letter/p/9f8e36/32.png) [@Peter\_Niederwieser](https://discuss.gradle.org/u/Peter_Niederwieser)\
**Post date:** [January 16, 2014, 8:04pm UTC](https://discuss.gradle.org/t/why-would-a-task-with-several-output-directories-be-considered-up-to-date-if-the-directories-dont-exist-yet/7463/13 "2014-01-16T20:04:00Z")

</div>

The idea is that a task that has no or empty inputs has nothing to do, and is therefore up-to-date. Not sure how exactly you were affected by this, but I’m glad that you were able to solve your problem.