Upper or lower case error messages?

[matklad]

I've noticed that all examples at https://docs.rs/anyhow/latest/anyhow/ use upper case error messages. This feels a bit odd, as I think the stdlib practice is to use lowercase error messages. There's also inconsistency with thiserror examples:

// anyhow repo: 

#[derive(Error, Debug)]
pub enum FormatError {
    #[error("Invalid header (expected {expected:?}, got {found:?})")]
    InvalidHeader {
        expected: String,
        found: String,
    },
    #[error("Missing attribute: {0}")]
    MissingAttribute(String),
}

// thiserror repo:
#[derive(Error, Debug)]
pub enum DataStoreError {
    #[error("data store disconnected")]
    Disconnect(#[from] io::Error),
    #[error("the data for key `{0}` is not available")]
    Redaction(String),
    #[error("invalid header (expected {expected:?}, found {found:?})")]
    InvalidHeader {
        expected: String,
        found: String,
    },
    #[error("unknown data store error")]
    Unknown,
}

Would it be a good idea to send a PR changing anyhow examples to lowercase?

[piegamesde]

From https://doc.rust-lang.org/stable/std/error/trait.Error.html: "Error messages are typically concise lowercase sentences without trailing punctuation"

I think all libraries should follow that convention for consistency.