all: split reusable components into workspace crates

utils/src/errorfmt.rs

@@ -0,0 +1,23 @@
+use std::{
+    error::Error,
+    fmt::{Display, Formatter},
+};
+
+pub struct ErrorFmt<E>(pub E);
+
+impl<E: Error> Display for ErrorFmt<E> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let mut e_opt = Some(&self.0 as &dyn Error);
+        let mut first = true;
+        while let Some(e) = e_opt {
+            if first {
+                write!(f, "{}", e)?;
+                first = false;
+            } else {
+                write!(f, ": {}", e)?;
+            }
+            e_opt = e.source();
+        }
+        Ok(())
+    }
+}