[SOLVED] How to use `jacoco-report-aggregation` plugin in a Gradle multi module project?

How to use `jacoco-report-aggregation` plugin in a Gradle multi module project?

The source code is here: https://github.com/yvasyliev/telegram-forwarder-bot/tree/feature/multimodule

I have a Gradle multi module project. The sub-modules are:

telegram-forwarder-bot (a console application)
telegram-forwarder-starter (library)
telegram-forwarder-starter-logging (library)
telegram-forwarder-starter-reddit (library)
telegram-forwarder-starter-thymeleaf (library)

jacoco plugin is applied to all sub modules and JaCoCo report generation works as expected in each submodule.

Now I want to aggregate JaCoCo reports from submodules in a single report.

I applied jacoco-report-aggregation plugin and added the following code to the root build.gradle:

plugins {
    id 'jacoco-report-aggregation'
}

dependencies {
    jacocoAggregation project(':telegram-forwarder-bot')
}

reporting {
    reports {
        testCodeCoverageReport(JacocoCoverageReport) {
            testSuiteName = "test"
        }
    }
}

When I try to execute ./gradlew testCodeCoverageReport, I'm getting the following error:

[Incubating] Problems report is available at: file:///C:/Users/Yevhen/IdeaProjects/reddit-telegram-forwarder/build/reports/problems/problems-report.html

FAILURE: Build failed with an exception.

* What went wrong:
Could not determine the dependencies of task ':testCodeCoverageReport'.
> Could not resolve all dependencies for configuration ':aggregateCodeCoverageReportResults'.
   > Could not resolve project :telegram-forwarder-bot.
     Required by:
         root project :
      > Unable to find a matching variant of root project ::
          - No variants exist.

* Try:
> Creating consumable variants is explained in more detail at https://docs.gradle.org/8.14.3/userguide/declaring_dependencies.html#sec:resolvable-consumable-configs.
> Review the variant matching algorithm at https://docs.gradle.org/8.14.3/userguide/variant_attributes.html#sec:abm_algorithm.
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
> Get more help at https://help.gradle.org.

BUILD FAILED in 3s

Could you please help me to make jacoco-report-aggregation plugin work?

Solution

Most likely I was getting this error because the root module and a submodule shared the same name. When I changed the root module name I was able to aggregate jacoco report.