This is caused by
https://issues.apache.org/jira/browse/SUREFIRE-951
https://issues.apache.org/jira/browse/SUREFIRE-1220
The solution is to add a argLine:
<plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <version>2.15</version> <configuration> <argLine>-Dfile.encoding=${project.build.sourceEncoding}</argLine> </configuration> </plugin>