no-std compilation issue

[libesz]

Hey!
I am trying to use CXX to compile Rust and C++ to an embedded arm platform (STM32F4). I found earlier discussions and PRs about this topic and as I understood it should work, so maybe I am still doing something wrong.

Using this to avoid std usage:

cxx = { version = "1.0.110", default-features = false, features = ["alloc"] }

and the build still gives me this:

rust-lld: error: unable to find library -lstdc++

I've put the demo project here: https://github.com/libesz/temp-rust-cxx-demo