rust-lld: error: undefined symbol: memchr when compiling with nightly-aarch64-unknown-linux-musl

[yogh333]

Hello,

I have an undefined symbol error when trying to compile qrcodegen.c with toolchain nightly-aarch64-unknown-linux-musl:

 rust-lld: error: undefined symbol: memchr
          >>> referenced by qrcodegen.c:964 (/apps/ledger-device-rust-sdk/target/stax/debug/build/ledger_secure_sdk_sys-d4f9f369bf0ebeb9/out/ledger-secure-sdk/qrcode/src/qrcodegen.c:964)
          >>>               8ea603dc3489e912-qrcodegen.o:(qrcodegen_isAlphanumeric) in archive /apps/ledger-device-rust-sdk/target/stax/debug/deps/libledger_secure_sdk_sys-4bf5710c68e34674.rlib
          >>> referenced by qrcodegen.c:1093 (/apps/ledger-device-rust-sdk/target/stax/debug/build/ledger_secure_sdk_sys-d4f9f369bf0ebeb9/out/ledger-secure-sdk/qrcode/src/qrcodegen.c:1093)
          >>>               8ea603dc3489e912-qrcodegen.o:(qrcodegen_makeAlphanumeric) in archive /apps/ledger-device-rust-sdk/target/stax/debug/deps/libledger_secure_sdk_sys-4bf5710c68e34674.rlib

part of qrcodegen source code raising the error is below:

// Public function - see documentation comment in header file.
bool qrcodegen_isAlphanumeric(const char *text)
{
    assert(text != NULL);
    for (; *text != '\0'; text++) {
        if (strchr(ALPHANUMERIC_CHARSET, *text) == NULL) {
            return false;
        }
    }
    return true;
}

For your information, I am using the following unstable feature in my .cargo/config.toml:

[unstable]
build-std = ["core", "alloc"]
build-std-features = ["compiler-builtins-mem"]

I do not know if I provide enough information to get help, please tell me.
Thanks for your support 🙏

[adamgemmell]

Most likely you don't have an aarch64 musl libc available if the linker reports an undefined symbol that is meant to come from libc.

Possibly similar to #76 where adding -Lpath/to/self-contained fixes things. Your example originates in C code but if you have a concise reproduction of the issue that'd be very helpful.