When building a Zero JVM variant of a JDK 10 tree with JDK-8174962 one gets:

Optimizing the exploded image
/disk/openjdk/upstream-sources/openjdk-hs/build/linux-x86_64-normal-zero-release/jdk/bin/java -Xms64M -Xmx1600M -XX:ThreadStackSize=1536 -XX:+UseSerialGC -Xms32M -Xmx512M -XX:TieredStopAtLevel=1 -cp /disk/openjdk/upstream-sources/openjdk-hs/build/linux-x86_64-normal-zero-release/buildtools/tools_jigsaw_classes --add-exports java.base/jdk.internal.module=ALL-UNNAMED build.tools.jigsaw.AddPackagesAttribute /disk/openjdk/upstream-sources/openjdk-hs/build/linux-x86_64-normal-zero-release/jdk
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (os_linux_zero.cpp:271), pid=30991, tid=30992
# fatal error: caught unhandled signal 11
#
# JRE version: (10.0) (build )
# Java VM: OpenJDK 64-Bit Zero VM (10-internal+0-adhoc.sgehwolf.openjdk-hs, interpreted mode, serial gc, linux-amd64)
# Core dump will be written. Default location: Core dumps may be processed with "/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %e" (or dumping to /disk/openjdk/upstream-sources/openjdk-hs/make/core.30991)
#
# An error report file with more information is saved as:
# /disk/openjdk/upstream-sources/openjdk-hs/make/hs_err_pid30991.log
#
# If you would like to submit a bug report, please visit:
# http://bugreport.java.com/bugreport/crash.jsp
#
gmake[3]: *** [ExplodedImageOptimize.gmk:41: /disk/openjdk/upstream-sources/openjdk-hs/build/linux-x86_64-normal-zero-release/jdk/_packages_attribute.done] Aborted (core dumped)
gmake[3]: Leaving directory '/disk/openjdk/upstream-sources/openjdk-hs/make'
gmake[2]: *** [make/Main.gmk:361: exploded-image-optimize] Error 2
gmake[2]: Leaving directory '/disk/openjdk/upstream-sources/openjdk-hs'

One such tree is current http://hg.openjdk.java.net/jdk/jdk