I also had to update my Rust to nightly. Thanks for the hint.
I was a little stupid about installing libsodium on windows, so to document it somewhere, I did this. (for a 64 bit windows system)
- download https://download.libsodium.org/libsodium/releases/libsodium-1.0.2.tar.gz
- cd crust (or cd routing)
- mkdir bin
- cd bin
- mkdir x86_64-pc-windows-gnu
- copy from the libsodium-1.0.2.tar.gz archive, only the libsodium.a file into the new bin/x86_64-pc-windows-gnu directory just made
[@happybeing added to the OP thanks]