Hotspot produced this error report.

NB: There are significant modifications to java.util.HashMap that
utilize inline classes. There is at least some unknown bug in
the Hashmap implementation. In some cases it has resulted in corrupted classfiles.

# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=/gcm.cpp:526
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (open/src/hotspot/share/opto/gcm.cpp:526), pid=26570, tid=26594
# assert(load_alias_idx || (load->is_Mach() && load->as_Mach()->ideal_Opcode() == Op_StrComp)) failed: String compare is only known 'load' that does not conflict with any stores
#
# JRE version: Java(TM) SE Runtime Environment (14.0) (fastdebug build 14-lworldea+0-2019-10-26-1616424.rriggs.valhalla-dev)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 14-lworldea+0-2019-10-26-1616424.rriggs.valhalla-dev, mixed mode, tiered, compressed oops, g1 gc, linux-amd64)
# Problematic frame:
# V [libjvm.so+0xd205d1] PhaseCFG::insert_anti_dependences(Block*, Node*, bool)+0xe1
#
# Core dump will be written. Default location: Core dumps may be processed with "/usr/share/apport/apport %p %s %c %d %P" (or dumping to .../valhalla-dev/open/core.26570)
#
# An error report file with more information is saved as:
# .../valhalla-dev/open/hs_err_pid26570.log
#
# Compiler replay data is saved as:
# .../valhalla-dev/open/replay_pid26570.log
#
# If you would like to submit a bug report, please visit:
# http://bugreport.java.com/bugreport/crash.jsp
#
Current thread is 26594
Dumping core ...
Error: Compilation of extra property definition files failed. rc=134

At the time, jtreg was invoking javac to generate the VMProps.class.