The test java/lang/String/concat/CompactStringsInitialCoder.java crashed once during some test run with the following stack trace with the latest jdk/jdk tree:

# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x000000010b949457, pid=5168, tid=21763
#
# JRE version: Java(TM) SE Runtime Environment (13.0) (fastdebug build 13-internal+0-2019-01-09-1319023.thomas.schatzl.hs)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 13-internal+0-2019-01-09-1319023.thomas.schatzl.hs, compiled mode, compressed oops, g1 gc, bsd-amd64)
# Problematic frame:
# V  [libjvm.dylib+0x949457]  Matcher::Label_Root(Node const*, State*, Node*, Node const*)+0x3ab
#
# Core dump will be written. Default location: /cores/core.5168
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.java.com/bugreport/crash.jsp

Stack: [0x0000700002d8d000,0x0000700002e8d000],  sp=0x0000700002e89150,  free space=1008k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.dylib+0x949457]  Matcher::Label_Root(Node const*, State*, Node*, Node const*)+0x3ab
V  [libjvm.dylib+0x94958a]  Matcher::Label_Root(Node const*, State*, Node*, Node const*)+0x4de
V  [libjvm.dylib+0x946447]  Matcher::match_tree(Node const*)+0x1ad
V  [libjvm.dylib+0x945cd7]  Matcher::xform(Node*, int)+0x583
V  [libjvm.dylib+0x9441f1]  Matcher::match()+0x82b
V  [libjvm.dylib+0x3a5007]  Compile::Code_Gen()+0x7d
V  [libjvm.dylib+0x3a2dae]  Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int, bool, bool, bool, DirectiveSet*)+0xc98
V  [libjvm.dylib+0x2ce91d]  C2Compiler::compile_method(ciEnv*, ciMethod*, int, DirectiveSet*)+0xed
V  [libjvm.dylib+0x3b628f]  CompileBroker::invoke_compiler_on_method(CompileTask*)+0x5c1
V  [libjvm.dylib+0x3b5b16]  CompileBroker::compiler_thread_loop()+0x1ec
V  [libjvm.dylib+0xb923cc]  JavaThread::thread_main_inner()+0x1fe
V  [libjvm.dylib+0xb91ea0]  JavaThread::run()+0x2ac
V  [libjvm.dylib+0xb8e5eb]  Thread::call_run()+0x149
V  [libjvm.dylib+0x9f50ec]  thread_native_entry(Thread*)+0x149
C  [libsystem_pthread.dylib+0x3661]  _pthread_body+0x154
C  [libsystem_pthread.dylib+0x350d]  _pthread_body+0x0
C  [libsystem_pthread.dylib+0x2bf9]  thread_start+0xd

This looks like the same stack trace as in JDK-8205033, but this one has been fixed half a year ago so I created a new issue.

While the build had changes to the GC pause in it, no GC events occurred yet, so highly unlikely that these were caused by that.

Tried to reproduce by running the test a further 160 times on all platforms with no further crash. hs_err file attached.