re-export curve25519-dalek features from libsignal-client

[nworbnhoj]

I recently opened an issue/request for libsignal-client to re-export curve25519-dalek features

Assuming this request is successful I hope that libsignal-service-rs/Cargo.toml might also re-export curve25519-dalek features?

nightly = [libsignal-client/nightly]
default = [libsignal-client/default]
std = [libsignal-client/std]
alloc = [libsignal-client/alloc]
u32_backend = [libsignal-client/u32_backend]
u64_backend = [libsignal-client/u64_backend]
simd_backend = [libsignal-client/simd_backend]

In particular I am seeking std and u32_backend - and include the others for sake of completeness.

[rubdos]

What's the reasoning behind this? You can include curve25519-dalek yourself in Cargo.toml and set the desired feature set there, I'd think. Neither this crate nor libsignal-client need access to these features.

[nworbnhoj]

As I understand it - features can be specified at the command line or in Cargo.toml - but only in code with a direct dependency on libsignal-client (in this case). libsignal-service-rs must re-export these features for them to be available to subsequent dependents (such as presage or xous-core).

In my case (Signal App on the Precursor) I need to set default-features=false to disable the default u64_backend and then set feature=u32_backend

[rubdos]

I did a bit of digging, and indeed the default-features=false comes back to bite you.

I'll continue the discussion on signalapp/libsignal#453.