const bt_log_spec *log,
const src_location *const src, const mem_block *const mem,
const int lvl, const char *const tag, const char *const fmt, va_list va)
const bt_log_spec *log,
const src_location *const src, const mem_block *const mem,
const int lvl, const char *const tag, const char *const fmt, va_list va)