How to export a symbol from a Rust executable?

You can pass linker options to rustc, like:

$ rustc src/main.rs --crate-type bin -C link-args=-Wl,-export-dynamic
$ nm main|grep export
00000000000d79c4 R exported_symbol

You'll probably want to put this in your rustflags in your .cargo/config something like:

[target.x86_64-unknown-linux-gnu]
rustflags = [ "-C", "link-args=-Wl,-export-dynamic" ]