54     cause: Option<anyhow::Error>,  field
61         self.cause.as_ref().map(AsRef::as_ref)  in source()
68             .or_else(|| self.cause.as_deref().map(std::error::Error::description))  in description()
69             .expect("no message nor cause?")  in description()
80         if let Some(ref cause) = self.cause {  in fmt()
81             write!(f, "{prefix}{cause}")?;  in fmt()
83             panic!("no message nor cause?");  in fmt()
95             cause: None,  in from()
108             cause: None,  in from()
121             cause: Some(error),  in from()
130     /// description of `cause`
132     pub fn with_error(msg: impl Into<Cow<'static, str>>, cause: impl Into<anyhow::Error>) -> Self {  in with_error()
136             cause: Some(cause.into()),  in with_error()
306                 cause: None,  in cloned_from_foreign()
364             &*format!("{}", Error::with_error("msg", anyhow!("cause"))),  in test_display()
365             "msg: cause"  in test_display()