bash failed to start with valgrind

Test with latest bash (commit 637f5c8696a6adc9b4519f1), x86_64,
I try to execute bash with valgrind,  it failed.

How to reproduce.
$  valgrind --mem-leak=full ./bash
malloc: variables.c:658: assertion botched
free: called with unallocated block argument
last command: (null)
Aborting...==208360==
==208360== Process terminating with default action of signal 6
(SIGABRT): dumping core
==208360==    at 0x49287D4: __pthread_kill_implementation (pthread_kill.c:44)
==208360==    by 0x48CF39D: raise (raise.c:26)
==208360==    by 0x48B6991: abort (abort.c:100)
==208360==    by 0x42D614: programming_error (error.c:162)
==208360==    by 0x4D4CB1: internal_free.isra.0 (malloc.c:963)
==208360==    by 0x42BCD7: initialize_shell_variables (variables.c:658)
==208360==    by 0x403F65: shell_initialize (shell.c:1963)
==208360==    by 0x40285F: main (shell.c:580)
==208360==
==208360== HEAP SUMMARY:
==208360==     in use at exit: 14,068 bytes in 60 blocks
==208360==   total heap usage: 81 allocs, 21 frees, 30,535 bytes allocated
==208360==
==208360== LEAK SUMMARY:
==208360==    definitely lost: 0 bytes in 0 blocks
==208360==    indirectly lost: 0 bytes in 0 blocks
==208360==      possibly lost: 0 bytes in 0 blocks
==208360==    still reachable: 14,068 bytes in 60 blocks
==208360==         suppressed: 0 bytes in 0 blocks
==208360== Reachable blocks (those to which a pointer was found) are not shown.
==208360== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==208360==
==208360== For lists of detected and suppressed errors, rerun with: -s
==208360== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)
Aborted (core dumped)

I can reproduce this issue 100%.

(gdb) bt
#0  __pthread_kill_implementation (threadid=<optimized out>,
signo=signo@entry=6,
    no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x0000000004928843 in __pthread_kill_internal (threadid=<optimized
out>, signo=6)
    at pthread_kill.c:78
#2  0x00000000048cf39e in __GI_raise (sig=sig@entry=6) at
../sysdeps/posix/raise.c:26
#3  0x00000000048b6992 in __GI_abort () at abort.c:100
#4  0x000000000042d615 in programming_error (format=<optimized out>)
at error.c:162
#5  0x00000000004d4c26 in xbotch (s=<optimized out>,
file=file@entry=0x4f9cac "variables.c",
    line=line@entry=658, e=2, mem=0x4aaff20) at malloc.c:382
#6  0x00000000004d4cb2 in internal_free (mem=mem@entry=0x4aaff20,
    file=file@entry=0x4f9cac "variables.c", line=line@entry=658,
flags=1) at malloc.c:963
#7  0x00000000004d6005 in sh_free (mem=mem@entry=0x4aaff20,
    file=file@entry=0x4f9cac "variables.c", line=line@entry=658) at
malloc.c:1408
#8  0x00000000004779ba in sh_xfree (string=string@entry=0x4aaff20,
    file=file@entry=0x4f9cac "variables.c", line=line@entry=658) at
xmalloc.c:223
#9  0x000000000042bcd8 in initialize_shell_variables (env=<optimized
out>, privmode=0)
    at variables.c:658
#10 0x0000000000403f66 in shell_initialize () at shell.c:1963
#11 0x0000000000402860 in main (argc=1, argv=0x1ffefffbb8,
env=0x1ffefffbc8) at shell.c:580

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