more review stuff

src/backend/actual/pacman.rs

@@ -67,6 +67,10 @@ impl Backend for Pacman {
         cmd.status()
             .with_context(|| format!("running command [{cmd:?}]"))
     }
+
+    fn supports_assigning_packages_as_dependency(&self) -> bool {
+        true
+    }
 }
 
 fn get_all_installed_packages_from_alpm() -> Result<HashSet<String>> {

src/backend/actual/rust.rs

@@ -31,6 +31,10 @@ impl Backend for Rust {
         self.get_all_installed_packages()
             .context("getting all installed packages")
     }
+
+    fn supports_assigning_packages_as_dependency(&self) -> bool {
+        false
+    }
 }
 
 fn extract_packages(json: Value) -> Result<HashSet<Package>> {

src/backend/backend_trait.rs

@@ -33,6 +33,8 @@ pub(crate) trait Backend {
             .with_context(|| format!("running command {cmd:?}"))
     }
 
+    fn supports_assigning_packages_as_dependency(&self) -> bool;
+
     /// Remove the specified packages.
     fn remove_packages(&self, packages: &[Package]) -> Result<ExitStatus> {
         let mut cmd = Command::new(self.get_binary());