Checkstyle: Error:Execution failed for task ':app:checkstyle'. > Unable to create a Checker: configLocation{path}, classpath {null}.

[SUPERCILEX]

My gradle file:

apply plugin: 'checkstyle'
check.dependsOn 'checkstyle'

def configDir = "${project.rootDir}/quality"

checkstyle {
    toolVersion = '7.2'
}

task checkstyle(type: Checkstyle) {
    configFile file("$configDir/checkstyle/checkstyle.xml")
    configProperties.checkstyleSuppressionsPath = file("$configDir/checkstyle/suppressions.xml").absolutePath
    source 'src'
    include '**/*.java'
    exclude '**/gen/**'
    classpath = files()
}

I'm using this version of the google java style guide: https://github.com/checkstyle/checkstyle/commit/a1e1403df4478e161a1c9c5daf7607c362eca1f5

Gradle version: 3.3

checkstyle version 6.9 and lower:
Error:Execution failed for task ':app:checkstyle'. > Unable to create a Checker: cannot initialize module TreeWalker - Property 'scope' in module ParameterName does not exist, please check the documentation

checkstyle version 6.10 and higher:
Error:Execution failed for task ':app:checkstyle'. > Unable to create a Checker: configLocation{path}, classpath {null}.

[SUPERCILEX]

It works with this checkstyle for some reason: https://github.com/google/google-api-java-client/blob/dev/checkstyle.xml

[rnveach]

If you still have issues, please see http://checkstyle.sourceforge.net/report_issue.html#How_to_report_a_bug .

@SUPERCILEX

I'm using this version of the google java style guide: a1e1403

You may be trying to use a configuration that is too new for the version of checkstyle you are currently using. You are referencing code that is in version 7.3-SNAPSHOT which is not even released and your grade version is 7.2.

It works with this checkstyle for some reason: https://github.com/google/google-api-java-client/blob/dev/checkstyle.xml

That uses maven-checkstyle-plugin which defaults to Checkstyle version 6.11.2 and I didn't see an override in the pom.

I would start with the google config file that supports 7.2 and do any modification to fit your needs.
https://github.com/checkstyle/checkstyle/blob/5cb0f9d39aad100b31c28cd27c3f90a6835ed21d/src/main/resources/google_checks.xml#L104 (7.2 google config)

[romani]

Please use version that is embeded to checkstyle jar.
You can wait till release of 7.3 , that will be at the end of the month.

[SUPERCILEX]

Thanks! That explains things.

[Fengcoder]

在buildscipt 里面的 dependencies 中添加 classpath 'com.puppycrawl.tools:checkstyle:7.1.2' , classpath 就不会为null