Glibc 2.33 deprecates the mallinfo API in favor of the new mallinfo2 API. The API stays nearly the same, only the types in the struct containing the malloc information has changed. Fields in the new API are size_t instead of int.

Compiling against glibc 2.33 triggers a warning (because of mallinfo deprecation), which becomes an error if --disable-warnings-as-errors is not used.

See https://sourceware.org/pipermail/libc-alpha/2021-February/122207.html