Spotless gradle is super slow and doesn't appear to respect the -PspotlessFiles flag

[dphart]

Using
id "com.diffplug.gradle.spotless" version "3.28.1"
I'm seeing a spotlessApply, which it thinks is cached, taking over a minute.

For this build I also ran it with the -PspotlessFiles=build.gradle flag, which I would think should cut down on the time to run but it's still taking over a minute. The only thing that changed was a single white space.

Am I missing something? Is this a typical run time? The project isn't massive.
https://scans.gradle.com/s/pcwl4s6sc7oio

spotless {
    enforceCheck = true
    java {
        target '**/*.java'
        targetExclude '**/.gradle/', '**/build/'
        removeUnusedImports()
        trimTrailingWhitespace()
        indentWithSpaces()
        endWithNewline()
        googleJavaFormat().aosp()
    }
    kotlin {
        target '**/*.kt'
        targetExclude '**/.gradle/', '**/build/'
        trimTrailingWhitespace()
        indentWithSpaces()
        endWithNewline()
        ktlint('0.36.0').userData(['disabled_rules': 'no-wildcard-imports'])
    }
    format 'xml', {
        target '**/*.xml'
        targetExclude '**/.idea/', '**/.gradle/', '**/build/'
        indentWithSpaces()
        trimTrailingWhitespace()
        endWithNewline()
    }
    format 'misc', {
        target '**/*.gradle', '**/*.md', '**/.gitignore'
        targetExclude '**/.gradle/', '**/build/'
        indentWithSpaces()
        trimTrailingWhitespace()
        endWithNewline()
    }
}

[nedtwigg]

Your build time is long because your targets are all **/*.xx. It would be a lot faster if it were instead src/xx/**/*.xx or *.xx. The time is being consumed in giant directory traversals looking for .xx files, then again in another giant traversal to look for .yy files, and so on.

With -PspotlessFiles, you're not specifying the target, you're just filtering it. So it still has to resolve every directory traversal, and then see if any of those files String#matches(String) the regex that you've passed (might want to escape the . by the way).

What are you using -PspotlessFiles for? Would #511 work for you?

[dphart]

So interesting find, Changing the way I bring in the plugin, it's now running in under 10 seconds. Using the older classpath 'com.diffplug.spotless:spotless-plugin-gradle:3.28.1 has helped.
I don't know why changing the way the dependency is imoported drastically changes run times.

#511 would roughly work, it looks like that's an open issue. They're trying to more or less achieve the same thing I am, and that Spotless only runs on files that have changed since the last commit.

[nedtwigg]

If you change back to the “slow” way, is it still slow? Or are they the same speed now? There’s a lot of caching going on, I wouldn’t expect any speed difference between the two approaches.

[nedtwigg]

Happy to reopen if you find more info, but I suspect that implementing #511 is going to be the final solution to this, -PspotlessFiles has proven to be tricky for people to use.