Bug#1106876: sscanf doesn't work in newlib

["Naveen Nathan" <debian@t.lastninja.net>]

Package: libnewlib-arm-none-eabi
Version: 4.4.0.20231231-2

It appears sscanf always returns 0 when compiling to a Raspberry Pi RP2040
using the gcc-arm-none-eabi toolchain with libstdc++ and newlib.

Here is a transcript of the code triggering the issue; I no longer have the device
to test further.


auto device::parse_version_string(const char *version) -> bool
{
    const char *input = "1";
    uint8_t one{};
    int matched = std::sscanf(input, "%hhu", &one);
    if (matched == 1) {
        LOGD.printf("FROG13: parsed '%s' into 1 components one=%d", input, one);
    } else {
        LOGD.printf("FROG13: failed to parse '%s' into 1 components, got %d components", inp
ut, matched);
    }
.
.
.
}

Yields: "FROG13: failed to parse '1' into 1 components, got 0 components"