[rust-lang/rust] rust-1.89 build failure due to "Undefined symbols for architecture x86_64"

### ROOT CAUSE The build failure occurs because the linker cannot find the C++ standard library symbols required for `std::bad_function_call`. This suggests the build process is not properly linking against the C++ runtime library, which is necessary for certain Rust-to-C++ interactions, especially when using features that involve exceptions or function pointers. ### CODE FIX To resolve the undefined symbols, we need to ensure the build links against the C++ standard library. Modify the build command to include the C++ library: ```bash RUSTFLAGS='-C link-args=-lstdcxx' cargo build ``` Or, if you're using a Makefile project, update the linker arguments: ```makefile LD_FLAGS += -lstdcxx ``` Alternatively, if the issue arises from using C++ features, enable the C++ runtime in your build configuration: ```toml [build] features = ["cxx"] ``` This should provide the necessary C++ library symbols and resolve the build failure.