Compiler warnings on Debian 10

HI,

I was wondering if someone already has seen these warnings on Debian 10 (PostgreSQL 13.1):

../../../../src/include/port.h:176:70: warning: 'format' attribute argument not supported: gnu_printf
[-Wignored-attributes]
extern int pg_snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3, 4);
^
../../../../src/include/c.h:127:49: note: expanded from macro 'pg_attribute_printf'
#define pg_attribute_printf(f,a) __attribute__((format(PG_PRINTF_ATTRIBUTE, f, a)))
^
In file included from llvmjit_error.cpp:19:
In file included from ../../../../src/include/postgres.h:46:
In file included from ../../../../src/include/c.h:1318:
../../../../src/include/port.h:178:55: warning: 'format' attribute argument not supported: gnu_printf
[-Wignored-attributes]
extern int pg_sprintf(char *str, const char *fmt,...) pg_attribute_printf(2, 3);
^
../../../../src/include/c.h:127:49: note: expanded from macro 'pg_attribute_printf'
#define pg_attribute_printf(f,a) __attribute__((format(PG_PRINTF_ATTRIBUTE, f, a)))
^
In file included from llvmjit_error.cpp:19:
In file included from ../../../../src/include/postgres.h:46:
In file included from ../../../../src/include/c.h:1318:
../../../../src/include/port.h:180:58: warning: 'format' attribute argument not supported: gnu_printf
[-Wignored-attributes]
extern int pg_fprintf(FILE *stream, const char *fmt,...) pg_attribute_printf(2, 3);
^

Configure was successful:
...
configure: creating ./config.status
config.status: creating GNUmakefile
config.status: creating src/Makefile.global
config.status: creating src/include/pg_config.h
config.status: creating src/include/pg_config_ext.h
config.status: creating src/interfaces/ecpg/include/ecpg_config.h
config.status: linking src/backend/port/tas/dummy.s to src/backend/port/tas.s
config.status: linking src/backend/port/posix_sema.c to src/backend/port/pg_sema.c
config.status: linking src/backend/port/sysv_shmem.c to src/backend/port/pg_shmem.c
config.status: linking src/include/port/linux.h to src/include/pg_config_os.h
config.status: linking src/makefiles/Makefile.linux to src/Makefile.port

This is the official Debian AMI on AWS:
postgres(at)pg13:~/postgresql-13.1$ cat /etc/debian_version
10.8

Regards
Daniel