The full build isn't compatible with Java 11 yet, so you need both 8 and 11 configured in a toolchains.xml config. Then you need to use Java 8 as the default JVM (or at least the contents of JAVA_HOME), and the build will switch to higher version compilers for the modules that require it. Ideally, the build would be updated to simplify this, but it's a fairly difficult problem as it's still a relatively new area in Maven with multiple alternatives to how to support it.
On Tue, 8 Dec 2020 at 08:13, Volkan Yazıcı <volkan.yaz...@gmail.com> wrote: > Would you mind changing the default JDK you start *mvnw* to version 8 and > retrying via *./mvnw clean package -DskipTests*, please? (Here *clean* > goal is necessary for removing the class files compiled earlier with the > wrong JDK.) > [Sorry for the short answer, struggling with my day-job in the meantime.] > > On Tue, Dec 8, 2020 at 3:02 PM Joseph Tsai <jtsa0...@gmail.com> wrote: > >> Hi Volkan, >> >> I just installed both JDK8 and 11 and tried to do mvn clean install. The >> same error persists, and I think it's looking at my default Java >> installation? >> Running "sudo update-alternatives --config java" shows the following: >> [image: image.png] >> Currently it is defaulted to Java15, and everytime I change the default >> Java the wrong version circled in blue changes. >> [image: image.png] >> I also looked up what version 53 is, it is apparently Java9? >> >> My questions are: >> >> - Am I supposed to update the default Java to Java11 or 8? If not, is >> simply putting in more toolchain entries under toolchains.xml is enough? >> - How is Java9 related to the error message, if at all? >> - Honestly I am not sure what I'm supposed to do with the maven.yml >> example you linked... >> >> I have also attached a new copy of my updated toolchains.xml. A bit of >> information on my environment, I'm using Windows and do development through >> WSL2.0. >> >> Thanks once again, >> Joseph >> >> On Tue, 8 Dec 2020 at 22:44, Volkan Yazıcı <volkan.yaz...@gmail.com> >> wrote: >> >>> Hello Joseph, >>> >>> You need to have both JDK 8 and 11 installed and configured in your >>> toolchains.xml file. For reference, you can check how we do it in GitHub >>> Actions workflow: maven.yml >>> < >>> https://github.com/apache/logging-log4j2/blob/master/.github/workflows/maven.yml >>> > >>> and maven-toolchains.xml >>> < >>> https://github.com/apache/logging-log4j2/blob/master/.github/workflows/maven-toolchains.xml >>> >. >>> Once this is done, *./mvnw package -DskipTests* should succeed. Let us >>> know >>> if you encounter any further troubles. >>> >>> Kind regards. >>> >>> On Tue, Dec 8, 2020 at 12:22 PM Joseph Tsai <jtsa0...@gmail.com> wrote: >>> >>> > Hi everyone, >>> > >>> > I forked and cloned the project from GitHub >>> > <https://github.com/apache/logging-log4j2>. And spent the past couple >>> of >>> > hours trying to build from source with mvn install. >>> > >>> > It is failing with errors saying "class file has wrong version 55.0, >>> > should be 53.0" for "bad class file: >>> > /modules/java.base/java/util/EnumSet.class", which I think it means I >>> > probably need to find a Java 9 to install and build the project with? >>> But >>> > since Java 9 was discontinued, I haven't been able to find an Oracle >>> nor an >>> > OpenJDK version to install. >>> > >>> > I have attached an output txt file for maven install and my current >>> maven >>> > toolchain.xml if it helps clarifying what I might have been doing >>> wrong. >>> > >>> > Thanks, >>> > Joseph >>> > >>> >>
