"an input to unknown location has changed" with experiment-configuration-cache

[SimonMarquis]

While upgrading to the new Develocity naming, the experiment-config-cache workflow started acting weird.

Specifically, the 2 Gradle run (in the same GHA job) does not re-use the configuration cache, because of "Calculating task graph as configuration cache cannot be reused because an input to unknown location has changed." as you can see here: https://github.com/SimonMarquis/SealedObjectInstances/actions/runs/12432422305/job/34712511059#step:4:259

And the corresponding Gradle Scan does not show what it is but "an input to unknown location has changed ": https://scans.gradle.com/s/46lwbdtmths4c/performance/configuration#summary-configuration-caching-cache-invalidation-reason

On my local environment it works as expected. The configuration cache is first stored, then restored on 2nd run.

Any tips on how to debug this further?

EDIT: --info does not seem to be helpful.
EDIT: using Gradle 8.11.1

[SimonMarquis]

I found 3 interesting things from the Gradle configuration cache reports:

• GIT_TRACE_PERFORMANCE input (env variable) is in the 1st execution only
• durian.plugins.com.diffplug.common.base.Errors.Plugins.Log input (system property) is also in the 1st execution
• there are 40 files from .gradle/caches/modules-2/ that are also part of the 1st execution only.

[erichaagdev]

Hi, @SimonMarquis. Thanks for taking the time to report this.

I can't think of a reason why the rename would cause this. My first theory is it has something to do with the setup-gradle step that we include, though I haven't been able to investigate deeply. If you don't mind experimenting, I wonder if you could try to copy the action and exclude the setup-gradle step to see if it helps at all. Please let me know.

[SimonMarquis]

Unfortunately I got the same result: "Calculating task graph as configuration cache cannot be reused because an input to unknown location has changed."

https://github.com/SimonMarquis/SealedObjectInstances/actions/runs/12433656005?pr=313

[SimonMarquis]

It seems like that configuring Gradle with my own setup-gradle solved the issue. 🎉
I tried to also force the cache-disabled: true but it worked the same way 🤷

[SimonMarquis]

It seems like to only appear when running on the main (default) branch 🤔

[SimonMarquis]

Clearing GitHub action's cache fixes the issue, for 1 build...
Then it fails again 🤯

[erichaagdev]

Hi @SimonMarquis. Is this still an issue? I see your latest runs are successful.

[SimonMarquis]

I'm not 100% sure why/how it happens since Gradle does not really say what the input change is. The attempts only show flakiness when clearing the entire cache.
I suspected the issue was coming from spotless that I recently upgraded to a beta version, and I ended up reverting it.
I'll see when the stable version is released if the issue persists.

[SimonMarquis]

Indeed, this is still happening now with the same Cache miss reason: an input to unknown location has changed.

[erichaagdev]

@SimonMarquis I don't believe this is an issue with the scripts or the experiment. We eliminated the possibility that it was caused by the rename by copying & pasting the action code.

I see this issue gradle/gradle#25469 that seems to be related to the error you're seeing. I would ask you to give it a 👍, but I see you already have. Since you seem to be able to reproduce it, perhaps you could share the steps to do so over in that issue?

I am going to go ahead and close this issue since we determined this is not an issue caused by this project.