==36961== Memcheck, a memory error detector
==36961== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==36961== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==36961== Command: php index.php
==36961== 
==36961== Invalid read of size 1
==36961==    at 0x7B6CF40: zend_string_copy (zend_string.h:194)
==36961==    by 0x7B6CF40: xdebug_debugger_set_program_name (debugger.c:104)
==36961==    by 0x7B558EB: xdebug_execute_user_code_begin (base.c:731)
==36961==    by 0x488A58: ??? (in /usr/bin/php8.1)
==36961==    by 0x460CFF: zend_execute (in /usr/bin/php8.1)
==36961==    by 0x3F0D1F: zend_execute_scripts (in /usr/bin/php8.1)
==36961==    by 0x38B9E9: php_execute_script (in /usr/bin/php8.1)
==36961==    by 0x4D9E5D: ??? (in /usr/bin/php8.1)
==36961==    by 0x230096: ??? (in /usr/bin/php8.1)
==36961==    by 0x5157D8F: (below main) (libc_start_call_main.h:58)
==36961==  Address 0x4 is not stack'd, malloc'd or (recently) free'd
==36961== 
==36961== 
==36961== Process terminating with default action of signal 11 (SIGSEGV)
==36961==  Access not within mapped region at address 0x4
==36961==    at 0x7B6CF40: zend_string_copy (zend_string.h:194)
==36961==    by 0x7B6CF40: xdebug_debugger_set_program_name (debugger.c:104)
==36961==    by 0x7B558EB: xdebug_execute_user_code_begin (base.c:731)
==36961==    by 0x488A58: ??? (in /usr/bin/php8.1)
==36961==    by 0x460CFF: zend_execute (in /usr/bin/php8.1)
==36961==    by 0x3F0D1F: zend_execute_scripts (in /usr/bin/php8.1)
==36961==    by 0x38B9E9: php_execute_script (in /usr/bin/php8.1)
==36961==    by 0x4D9E5D: ??? (in /usr/bin/php8.1)
==36961==    by 0x230096: ??? (in /usr/bin/php8.1)
==36961==    by 0x5157D8F: (below main) (libc_start_call_main.h:58)
==36961==  If you believe this happened as a result of a stack
==36961==  overflow in your program's main thread (unlikely but
==36961==  possible), you can try to increase the size of the
==36961==  main thread stack using the --main-stacksize= flag.
==36961==  The main thread stack size used in this run was 8388608.
==36961== 
==36961== HEAP SUMMARY:
==36961==     in use at exit: 4,562,583 bytes in 30,685 blocks
==36961==   total heap usage: 37,656 allocs, 6,971 frees, 6,036,168 bytes allocated
==36961== 
==36961== LEAK SUMMARY:
==36961==    definitely lost: 27,809 bytes in 867 blocks
==36961==    indirectly lost: 40 bytes in 1 blocks
==36961==      possibly lost: 2,970,746 bytes in 22,018 blocks
==36961==    still reachable: 1,563,988 bytes in 7,799 blocks
==36961==         suppressed: 0 bytes in 0 blocks
==36961== Rerun with --leak-check=full to see details of leaked memory
==36961== 
==36961== For lists of detected and suppressed errors, rerun with: -s
==36961== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

(gdb) run
Starting program: /usr/bin/php index.php
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
xdebug_debugger_set_program_name (filename=0x0) at /tmp/pear/temp/xdebug/src/debugger/debugger.c:104
104                     XG_DBG(context).program_name = zend_string_copy(filename);
(gdb) bt full
#0  xdebug_debugger_set_program_name (filename=0x0) at /tmp/pear/temp/xdebug/src/debugger/debugger.c:104
No locals.
#1  0x00007ffff508f8ec in xdebug_execute_user_code_begin (execute_data=<optimized out>) at /tmp/pear/temp/xdebug/src/base/base.c:731
        op_array = 0x555555dd7d60
        edata = 0x0
        fse = <optimized out>
#2  0x00005555558d4a59 in ?? ()
No symbol table info available.
#3  0x00005555558acd00 in zend_execute ()
No symbol table info available.
#4  0x000055555583cd20 in zend_execute_scripts ()
--Type <RET> for more, q to quit, c to continue without paging--<RET>
No symbol table info available.
#5  0x00005555557d79ea in php_execute_script ()
No symbol table info available.
#6  0x0000555555925e5e in ?? ()
No symbol table info available.
#7  0x000055555567c097 in ?? ()
No symbol table info available.
#8  0x00007ffff74e8d90 in __libc_start_call_main (main=main@entry=0x55555567bcc0, argc=argc@entry=2, argv=argv@entry=0x7fffffffe058) at ../sysdeps/nptl/libc_start_call_main.h:58
        self = <optimized out>
        result = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {0, 4536979451957479101, 140737488347224, 93824993443008, 93824997203416, 140737354125376, -4536979453019420995, -4536962817066006851}, 
              mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x7fffffffe058, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = -8104}}}
        not_first_call = <optimized out>
#9  0x00007ffff74e8e40 in __libc_start_main_impl (main=0x55555567bcc0, argc=2, argv=0x7fffffffe058, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffe048)
    at ../csu/libc-start.c:392
No locals.
#10 0x000055555567d1f5 in _start ()
No symbol table info available.