Jacoco report aggregation plugin is not generating the XML file

I'm working on a multi-module project that employs a standalone sub-project to aggregate coverage reports. The project is build using Gradle, employing the Jacoco report aggregation plugin for Gradle.

Currently, the coverage report is generated in HTML format only. However, I specifically need the XML file format so that I can incorporate it into an artifact within Azure DevOps pipeline.

The root project and sub-projects have the following build.grade configuration files:

Root project

plugins {
    id 'java'
}   
sourceCompatibility = '17'
allprojects {
    repositories {
        mavenCentral()
    }    
    tasks.withType(Test.class).tap {
        configureEach {
            useJUnitPlatform()
        }
    }
}

One of the sub-projects

plugins {
    id 'java'
    id 'jacoco'
}
dependencies {
   ...
}

The standalone coverage sub-project

 plugins {
   id 'java'     
   id 'jacoco-report-aggregation'
}
bootJar {
    enabled = false
}
jar {
    enabled = false
}    
dependencies {
    jacocoAggregation project(':sub-project1')
    jacocoAggregation project(':sub-project2')  
  }

The root project settings.gradle file, just for completeness:

rootProject.name = 'my root project'
include 'sub-project1'
include 'sub-project2'
include 'coverage'

To generate the reports I'm using the following Gradle command:

> gradle clean build jacocoTestReport 

In a different project with no sub-projects, I was able to generate the XML file by configuring up the Jacoco plugin report like this:

build.grade

jacocoTestReport {
  reports {
    xml.required = true
    csv.required = false
}   

Yet, I haven't be able to generate the XML format so far, for the multi-module project.

Any suggestions or clues wild be greatly appreciated.

The solutions can be found in this sample from the Gradle site.

The root and sub-projects build.settigns files are correct in my question. But for the coverage project the build.settings is missing a dependency The corrected file should be:

plugins {
   id 'java'     
   id 'jacoco-report-aggregation'
}
bootJar {
    enabled = false
}
jar {
    enabled = false
}    
dependencies {
    jacocoAggregation project(':sub-project1')
    jacocoAggregation project(':sub-project2')  
}
//as in sample for the case you want to build the report when you run check
tasks.named('check') {
    dependsOn tasks.named('testCodeCoverageReport', JacocoReport)
}

And to generate the aggregate report the command line should be:

$ ./gradlew testCodeCoverageReport 

Note that invoking the task jacocoTestReport will not build the aggregate report.

The report will be generated at <coverage project path>/build/reports/jacoco/testCodeCoverageReport.

The XML file will also be generate there there. It's not necessary to enable CSV report format with the aggregate report plugin.