Empty surefire reports when a multi-module project is ran with multiple report directories in surefire-report configuration

With a multi-module project, if the reporting configuration set multiple report directories (in the parent POM), then the report / report-only goals generate empty report.

The main / aggregated report says this is 0 Tests.
Module reports are empty html files.

The attached project is a sample project to reproduce this ...

The parent POM reporting conf explicitely set 2 reporting directories.

From the "parent" POM :

• mvn surefire-report:report ==> normal report per modules, nothing to say
• mvn clean
• mvn surefire-report:report -Daggregate=true ==> parent report with 0 tests, empty html report for modules
• mvn surefire-report:report; mvn surefire-report:report-only -Daggregate=true ==> idem, parent report with 0 tests, empty html report for modules