use downcasting for configuring backend objects

crates/pacdef_core/src/backend/actual/arch.rs

@@ -8,7 +8,7 @@ use anyhow::{Context, Result};
 use crate::backend::backend_trait::{Backend, Switches, Text};
 use crate::{impl_backend_constants, Group, Package};
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Arch {
     pub(crate) binary: String,
     pub(crate) aur_rm_args: Option<Vec<String>>,

crates/pacdef_core/src/backend/actual/rust.rs

@@ -9,7 +9,7 @@ use serde_json::Value;
 use crate::backend::backend_trait::{Backend, Switches, Text};
 use crate::{impl_backend_constants, Group, Package};
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Rust {
     pub(crate) packages: HashSet<Package>,
 }