codex/codex-rs/codex-auth/src/error.rs

#[derive(Debug)]
pub struct EnvVarError {
    pub var: String,
    pub instructions: Option<String>,
}

impl std::fmt::Display for EnvVarError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "Missing environment variable: `{}`.", self.var)?;
        if let Some(instructions) = &self.instructions {
            write!(f, " {instructions}")?;
        }
        Ok(())
    }
}