needs to be in a folder but:

```
cargo +nightly rustc -- --version --verbose
   Compiling postcard v1.0.9 (/Users/james/personal/postcard)
rustc 1.79.0-nightly (ccfcd950b 2024-04-15)
binary: rustc
commit-hash: ccfcd950b333fed046275dd8d54fe736ca498aa7
commit-date: 2024-04-15
host: aarch64-apple-darwin
release: 1.79.0-nightly
LLVM version: 18.1.3
```