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 > > >
<?xml version="1.0" encoding="UTF8"?> <toolchains> <toolchain> <type>jdk</type> <provides> <version>1.8</version> </provides> <configuration> <jdkHome>/usr/lib/jvm/java-8-openjdk-amd64</jdkHome> </configuration> </toolchain> <toolchain> <type>jdk</type> <provides> <version>11</version> </provides> <configuration> <jdkHome>/usr/lib/jvm/java-11-openjdk-amd64</jdkHome> </configuration> </toolchain> </toolchains>