Since JDK-8310233 has been implemented the arm32 build crashes with a segmentation fault:

/usr/bin/bash: line 1: 16703 Segmentation fault (core dumped) /workspace/build/linux-arm-server-release/jdk/bin/java -Xms64M -Xmx768M -cp /workspace/build/linux-arm-server-release/buildtools/tools_jigsaw_classes --add-exports java.base/jdk.internal.module=ALL-UNNAMED build.tools.jigsaw.AddPackagesAttribute /workspace/build/linux-arm-server-release/jdk > >(/usr/bin/tee -a /workspace/build/linux-arm-server-release/jdk/_optimize_image_exec.log) 2> >(/usr/bin/tee -a /workspace/build/linux-arm-server-release/jdk/_optimize_image_exec.log >&2)

I run arm32 builds on a raspberry pi using the following Dockerfile:

https://github.com/marchof/PiCI/blob/master/jdk/docker/Dockerfile