To reproduce, run HelloWebView on Ubuntu 20.04 as follows:

$ java HelloWebView https://gluonhq.com/

This will crash and generate a core file, but no hs_err_pid* file. Here is the stack trace from the core file:

(gdb) where
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007f0b53757859 in __GI_abort () at abort.c:79
#2 0x00007f0b10e55b63 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007f0b10eb2b4f in g_assertion_message_expr ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007f0b10fdf44e in ?? () from /lib/x86_64-linux-gnu/libpango-1.0.so.0
#5 0x00007f0b10fe01d8 in pango_itemize_with_base_dir ()
   from /lib/x86_64-linux-gnu/libpango-1.0.so.0
#6 0x00007f0b10fe02e9 in pango_itemize ()
   from /lib/x86_64-linux-gnu/libpango-1.0.so.0
#7 0x00007f0b346e65b0 in ?? ()
#8 0x00007f0b4c55bc20 in ?? ()
#9 0x0000000000000000 in ?? ()

The attached test program also reproduce this crash. In this case we do get an hs_err_pid* file.

$ java UnicodeTextTest
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x00007fa93dc0b2ac, pid=13889, tid=13906
#
# JRE version: Java(TM) SE Runtime Environment (14.0+36) (build 14+36-1461)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (14+36-1461, mixed mode, sharing, tiered, compressed oops, serial gc, linux-amd64)
# Problematic frame:
# C [libpango-1.0.so.0+0x1d2ac]
#
# Core dump will be written. Default location: Core dumps may be processed with "/usr/share/apport/apport %p %s %c %d %P %E" (or dumping to /home/kcr/javafx/tmp/core.13889)
#
# An error report file with more information is saved as:
# /home/kcr/javafx/tmp/hs_err_pid13889.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
#
Aborted (core dumped)


Here is the stack trace from the core dump file:
(gdb) where
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007fa98037e859 in __GI_abort () at abort.c:79
#2 0x00007fa97f40cf4b in os::abort(bool, void*, void const*) [clone .cold.64]
    () from /home/kcr/jdks/jdk-14/lib/server/libjvm.so
#3 0x00007fa97ff1aa86 in VMError::report_and_die(int, char const*, char const*, __va_list_tag*, Thread*, unsigned char*, void*, void*, char const*, int, unsigned long) () from /home/kcr/jdks/jdk-14/lib/server/libjvm.so
#4 0x00007fa97ff1b40b in VMError::report_and_die(Thread*, unsigned int, unsigned char*, void*, void*, char const*, ...) ()
   from /home/kcr/jdks/jdk-14/lib/server/libjvm.so
#5 0x00007fa97ff1b43e in VMError::report_and_die(Thread*, unsigned int, unsigned char*, void*, void*) () from /home/kcr/jdks/jdk-14/lib/server/libjvm.so
#6 0x00007fa97fd1237c in JVM_handle_linux_signal ()
   from /home/kcr/jdks/jdk-14/lib/server/libjvm.so
#7 0x00007fa97fd061f8 in signalHandler(int, siginfo*, void*) ()
   from /home/kcr/jdks/jdk-14/lib/server/libjvm.so
#8 <signal handler called>
#9 0x00007fa93dc0b2ac in ?? () from /lib/x86_64-linux-gnu/libpango-1.0.so.0
#10 0x00007fa93dc0b8c0 in ?? () from /lib/x86_64-linux-gnu/libpango-1.0.so.0
#11 0x00007fa93dc0d1c7 in pango_itemize_with_base_dir ()
   from /lib/x86_64-linux-gnu/libpango-1.0.so.0
#12 0x00007fa93dc0d2e9 in pango_itemize ()
   from /lib/x86_64-linux-gnu/libpango-1.0.so.0
#13 0x00007fa9606e65b0 in ?? ()
#14 0x00007fa978560800 in ?? ()
#15 0x0000000000000000 in ?? ()