RFC: minimum supported Rust version about libsignal-service-rs HOT 6 OPEN

error[E0658]: `match` is not allowed in a `const fn`
   --> /home/mersdk/.cargo/git/checkouts/libsignal-protocol-rs-bd2698d95a103c0d/2d00a19/libsignal-protocol/src/errors.rs:104:9
    |
104 | /         match code {
105 | |             sys::SG_ERR_NOMEM => Some(InternalError::NoMemory),
106 | |             sys::SG_ERR_INVAL => Some(InternalError::InvalidArgument),
107 | |             sys::SG_ERR_UNKNOWN => Some(InternalError::Unknown),
...   |
136 | |             _ => None,
137 | |         }
    | |_________^
    |
    = note: see issue #49146 <https://github.com/rust-lang/rust/issues/49146> for more information
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable

error[E0658]: `match` is not allowed in a `const fn`
   --> /home/mersdk/.cargo/git/checkouts/libsignal-protocol-rs-bd2698d95a103c0d/2d00a19/libsignal-protocol/src/errors.rs:142:9
    |
142 | /         match self {
143 | |             InternalError::NoMemory => sys::SG_ERR_NOMEM,
144 | |             InternalError::InvalidArgument => sys::SG_ERR_INVAL,
145 | |             InternalError::Unknown => sys::SG_ERR_UNKNOWN,
...   |
166 | |             InternalError::SerializationError => sys::SG_ERR_INVALID_PROTO_BUF,
167 | |         }
    | |_________^
    |
    = note: see issue #49146 <https://github.com/rust-lang/rust/issues/49146> for more information
    = help: add `#![feature(const_if_match)]` to the crate attributes to enable

error[E0658]: procedural macros cannot be expanded to expressions
  --> /home/mersdk/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-util-0.6.2/src/sync/poll_semaphore.rs:21:29
   |
21 |               inner: Box::pin(async_stream::stream! {
   |  _____________________________^
22 | |                 loop {
23 | |                     match semaphore.clone().acquire_owned().await {
24 | |                         Ok(permit) => yield permit,
...  |
27 | |                 }
28 | |             }),
   | |_____________^
   |
   = note: see issue #54727 <https://github.com/rust-lang/rust/issues/54727> for more information
   = help: add `#![feature(proc_macro_hygiene)]` to the crate attributes to enable