strange valgrind reports about wrapper_handler on 64-bit arm

Hi,

while running check-world on 64-bit arm (rpi5 with Debian 12.9), I got a
couple reports like this:

==64550== Use of uninitialised value of size 8
==64550== at 0xA62FE0: wrapper_handler (pqsignal.c:107)
==64550== by 0x580BB9E7: ??? (in
/usr/libexec/valgrind/memcheck-arm64-linux)
==64550== Uninitialised value was created by a stack allocation
==64550== at 0x4F94660: strcoll_l (strcoll_l.c:258)
==64550==
{
<insert_a_suppression_name_here>
Memcheck:Value8
fun:wrapper_handler
obj:/usr/libexec/valgrind/memcheck-arm64-linux
}
**64550** Valgrind detected 1 error(s) during execution of "ANALYZE
mcv_lists;"

The exact command varies, I don't think it's necessarily about analyze
or extended stats.

The line the report refers to is this:

(*pqsignal_handlers[postgres_signal_arg]) (postgres_signal_arg);

so I guess it can't be about postgres_signal_arg (as that's an int). But
that leaves just pqsignal_handlers, and why would that be uninitialized?

The closest thing I found in archives is [1] from about a year ago, but
we haven't found any clear explanation there either :-(

[1]
https://www.postgresql.org/message-id/f1a022e5-9bec-42c5-badd-cfc00b60515c@enterprisedb.com

regards

--
Tomas Vondra