'va_arg' with type 'long' was used for both 'int' and 'long' arguments, but x86_64 Linux has 64-bit 'long', so passing an 'int' argument to '_mi_vsnprintf` results in undefined behaviour.
'intptr_t' was used as the largest integer type, but on 32-bit systems it is 32-bit wide, while 'long long' is 64-bit. 'intmax_t' can be used instead.