Can't build with stable Rust due to use of include_str! in doc attribute

[VyrCossont]

Trying to build sysinfo 0.20.5 with stable Rust (currently the 2018 edition) results in the following compiler error, probably introduced by commit 0fdeb16:

error[E0658]: arbitrary expressions in key-value attributes are unstable
  --> /Users/user/.cargo/registry/src/git.luolix.top-1ecc6299db9ec823/sysinfo-0.20.5/src/lib.rs:10:10
   |
10 | #![doc = include_str!("../README.md")]
   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #78835 <https://github.com/rust-lang/rust/issues/78835> for more information

[GuillaumeGomez]

It also says in the README:

The minimum-supported version of rustc is 1.54.

The current stable is 1.55 so if you update your version it'll work.

[VyrCossont]

My mistake, still had 1.53 installed. Thanks for pointing that out.

I'd suggest adding rust-version = "1.54"¹² to Cargo.toml to enforce this requirement, but as of today, it's only supported by nightly Cargo behind the rust-version³ feature, and generates a warning on stable Cargo.

Footnotes

1. RFC: Minimum Supported Rust Version rust-lang/rfcs#2495 ↩

2. https://doc.rust-lang.org/nightly/cargo/reference/manifest.html#the-rust-version-field ↩

3. https://doc.rust-lang.org/cargo/reference/unstable.html#rust-version ↩

[GuillaumeGomez]

I'm still waiting for it hit stable before adding it. However I'll create an issue to not forget about it. Thanks!