$ export USE_ZEND_ALLOC=0
$ export ZEND_DONT_UNLOAD_MODULES=1
$ valgrind php test.php > valgrind.log 2>&1
Segmentation fault
$ cat valgrind.log 
==6070== Memcheck, a memory error detector
==6070== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al.
==6070== Using Valgrind-3.19.0 and LibVEX; rerun with -h for copyright info
==6070== Command: php test.php
==6070== 
==6070== Invalid read of size 8
==6070==    at 0x93A0AB8: zend_get_property_info_for_slot (zend_objects_API.h:102)
==6070==    by 0x93A0AB8: zend_get_typed_property_info_for_slot (zend_objects_API.h:108)
==6070==    by 0x93A0AB8: xdebug_get_property_type (var.c:866)
==6070==    by 0x93A2C0B: xdebug_object_element_export (var_export_line.c:75)
==6070==    by 0x93A2C0B: xdebug_var_export_line (var_export_line.c:296)
==6070==    by 0x93A2EB7: xdebug_get_zval_value_line (var_export_line.c:348)
==6070==    by 0x93BA3E4: add_single_value (stack.c:263)
==6070==    by 0x93BA3E4: xdebug_append_printable_stack (stack.c:443)
==6070==    by 0x93BB35B: xdebug_develop_throw_exception_hook (stack.c:871)
==6070==    by 0x93951C6: xdebug_throw_exception_hook (base.c:1476)
==6070==    by 0x93951C6: xdebug_throw_exception_hook (base.c:1428)
==6070==    by 0x21CD0A: zend_throw_exception_internal (in /usr/bin/php)
==6070==    by 0x2152D3: ??? (in /usr/bin/php)
==6070==    by 0x4445BB: execute_ex (in /usr/bin/php)
==6070==    by 0x93965BF: xdebug_execute_ex (base.c:830)
==6070==    by 0x20C251: ??? (in /usr/bin/php)
==6070==    by 0x4445BB: execute_ex (in /usr/bin/php)
==6070==  Address 0x70 is not stack'd, malloc'd or (recently) free'd
==6070== 
==6070== 
==6070== Process terminating with default action of signal 11 (SIGSEGV)
==6070==  Access not within mapped region at address 0x70
==6070==    at 0x93A0AB8: zend_get_property_info_for_slot (zend_objects_API.h:102)
==6070==    by 0x93A0AB8: zend_get_typed_property_info_for_slot (zend_objects_API.h:108)
==6070==    by 0x93A0AB8: xdebug_get_property_type (var.c:866)
==6070==    by 0x93A2C0B: xdebug_object_element_export (var_export_line.c:75)
==6070==    by 0x93A2C0B: xdebug_var_export_line (var_export_line.c:296)
==6070==    by 0x93A2EB7: xdebug_get_zval_value_line (var_export_line.c:348)
==6070==    by 0x93BA3E4: add_single_value (stack.c:263)
==6070==    by 0x93BA3E4: xdebug_append_printable_stack (stack.c:443)
==6070==    by 0x93BB35B: xdebug_develop_throw_exception_hook (stack.c:871)
==6070==    by 0x93951C6: xdebug_throw_exception_hook (base.c:1476)
==6070==    by 0x93951C6: xdebug_throw_exception_hook (base.c:1428)
==6070==    by 0x21CD0A: zend_throw_exception_internal (in /usr/bin/php)
==6070==    by 0x2152D3: ??? (in /usr/bin/php)
==6070==    by 0x4445BB: execute_ex (in /usr/bin/php)
==6070==    by 0x93965BF: xdebug_execute_ex (base.c:830)
==6070==    by 0x20C251: ??? (in /usr/bin/php)
==6070==    by 0x4445BB: execute_ex (in /usr/bin/php)
==6070==  If you believe this happened as a result of a stack
==6070==  overflow in your program's main thread (unlikely but
==6070==  possible), you can try to increase the size of the
==6070==  main thread stack using the --main-stacksize= flag.
==6070==  The main thread stack size used in this run was 8388608.
==6070== 
==6070== HEAP SUMMARY:
==6070==     in use at exit: 2,852,649 bytes in 23,683 blocks
==6070==   total heap usage: 27,161 allocs, 3,478 frees, 3,812,510 bytes allocated
==6070== 
==6070== LEAK SUMMARY:
==6070==    definitely lost: 23,136 bytes in 723 blocks
==6070==    indirectly lost: 40 bytes in 1 blocks
==6070==      possibly lost: 1,737,194 bytes in 13,709 blocks
==6070==    still reachable: 1,092,279 bytes in 9,250 blocks
==6070==         suppressed: 0 bytes in 0 blocks
==6070== Rerun with --leak-check=full to see details of leaked memory
==6070== 
==6070== For lists of detected and suppressed errors, rerun with: -s
==6070== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)