ADDITIONAL SYSTEM INFORMATION :
$ uname -a
Linux CPX-W32NYHUK7AU 5.10.102.1-microsoft-standard-WSL2 #1 SMP Wed Mar 2 00:30:59 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

./java -version
openjdk version "20-ea" 2023-03-21
OpenJDK Runtime Environment (build 20-ea+10-585)
OpenJDK 64-Bit Server VM (build 20-ea+10-585, mixed mode, sharing)

> ver
Microsoft Windows [Version 10.0.22000.856]

> java -version
openjdk version "18.0.2" 2022-07-19
OpenJDK Runtime Environment Temurin-18.0.2+9 (build 18.0.2+9)
OpenJDK 64-Bit Server VM Temurin-18.0.2+9 (build 18.0.2+9, mixed mode, sharing)

A DESCRIPTION OF THE PROBLEM :
jShell in versions 18 and 20 crashes when these two statements are entered:

var a = new Object()
var a = a

It works correctly with

Object a = new Object()
Object a = a

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1.) start jshell
2.) enter "var a = new Object()"
3.) enter "var a = a"

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
variable a is assigned to itself, no crash of jshell
ACTUAL -
crash, see stacktrace

CUSTOMER SUBMITTED WORKAROUND :
use "Object a = a" instead

FREQUENCY : always