Arch s390x has JRE but most builds of java needs jdk

logs from build on arch s390x

Setting up libsisu-plexus-java (0.3.3-3) ...

Setting up libmaven3-core-java (3.6.3-1) ...

Setting up default-jre-headless (2:1.11-72) ...

Setting up openjdk-11-jre-headless:s390x (11.0.11+9-0ubuntu2~20.04) ...

update-alternatives: using /usr/lib/jvm/java-11-openjdk-s390x/bin/java to provide /usr/bin/java (java) in auto mode

update-alternatives: using /usr/lib/jvm/java-11-openjdk-s390x/bin/jjs to provide /usr/bin/jjs (jjs) in auto mode

JRE is installed, and as result there are problems with build due to:

I tried to insdtall jdk8 by hack from JDK 8 and Maven missing in ARM64 despite `jdk: openjdk8` - #12 by native-api, but it does not work
here is example of failure: Travis CI - Test and Deploy with Confidence
Error: dl failure on line 894; Error: failed /usr/lib/jvm/adoptopenjdk-8-hotspot-s390x/jre/lib/s390x/server/libjvm.so, because libffi.so.6: cannot open shared object file: No such file or directory

execution on openjdk11 on “arch: ppc64le” also has problems with JAVA_HOME

Caused by: org.apache.maven.plugin.MojoExecutionException: MavenReportException: Error while generating Javadoc: Unable to find javadoc command: The environment variable JAVA_HOME is not correctly set.

to resolve problem with not set JAVA_HOME
I did small workaround - infra: setup JAVA_HOME · sevntu-checkstyle/sevntu.checkstyle@541081a · GitHub

      export JAVA_HOME="/usr/lib/jvm/"$(ls /usr/lib/jvm/ | head -n 1)"/"
      echo "JAVA_HOME="$JAVA_HOME
      export PATH=$JAVA_HOME/bin:$PATH