*warning: the following packages contain code that will be rejected by a future version of Rust: proc-macro-error2 v2.0.1*

Context: [pull/219#issuecomment-5050894288](https://github.com/8go/matrix-commander-rs/pull/219#issuecomment-5050894288)

```bash
cargo report future-incompatibilities --id 1
```

Output:

```
The following warnings were discovered during the build. These warnings are an
indication that the packages contain code that will become an error in a
future release of Rust. These warnings typically cover changes to close
soundness problems, unintended or undocumented behavior, or critical problems
that cannot be fixed in a backwards-compatible fashion, and are not expected
to be in wide use.

Each warning should contain a link for more information on what the warning
means and how to resolve it.

to solve this problem, you can try the following approaches:

- ensure the maintainers know of this problem (e.g. creating a bug report if needed)
or even helping with a fix (e.g. by creating a pull request)
- proc-macro-error2@2.0.1
- repository: https://github.com/GnomedDev/proc-macro-error-2
- detailed warning command: `cargo report future-incompatibilities --id 1 --package proc-macro-error2@2.0.1`

- use your own version of the dependency with the `[patch]` section in `Cargo.toml`
For more information, see:
https://doc.rust-lang.org/cargo/reference/overriding-dependencies.html#the-patch-section

The package `proc-macro-error2 v2.0.1` currently triggers the following future incompatibility lints:
> warning[E0365]: extern crate `proc_macro` is private and cannot be re-exported
> --> /home/ubuntu/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro-error2-2.0.1/src/lib.rs:494:13
> |
> 494 | pub use proc_macro;
> | ^^^^^^^^^^
> |
> = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
> = note: for more information, see issue #127909
> help: consider making the `extern crate` item publicly accessible
> |
> 277 | pub extern crate proc_macro;
> | +++
>
```