bug fix

src/dfx/src/commands/rules.rs

@@ -147,16 +147,16 @@ pub fn exec(env1: &dyn Environment, opts: RulesOpts) -> DfxResult {
         } else {
             output_file.write_fmt(format_args!(
                 "{}: {}\n",
-                make_target(graph, edge.source()),
-                make_target(graph, edge.target()),
+                make_target(graph, edge.source())?,
+                make_target(graph, edge.target())?,
             ))?;
         }
     }
     for node in graph0.nodes() {
         // TODO: `node.1` is a hack.
         let command = get_build_command(graph, *node.1);
         if let Some(command) = command {
-            output_file.write_fmt(format_args!("{}:\n\t{}\n\n", make_target(graph, *node.1), command))?;
+            output_file.write_fmt(format_args!("{}:\n\t{}\n\n", make_target(graph, *node.1)?, command))?;
         }
         if let Import::Canister(canister_name) = node.0 {
             output_file.write_fmt(format_args!("\ndeploy@{}: canister@{}\n", canister_name, canister_name))?;
@@ -181,19 +181,19 @@ pub fn exec(env1: &dyn Environment, opts: RulesOpts) -> DfxResult {
     Ok(())
 }
 
-fn make_target(graph: &Graph<Import, ()>, node_id: <Graph<Import, ()> as GraphBase>::NodeId) -> String {
+fn make_target(graph: &Graph<Import, ()>, node_id: <Graph<Import, ()> as GraphBase>::NodeId) -> DfxResult<String> {
     let node_value = graph.node_weight(node_id).unwrap();
-    match node_value {
+    Ok(match node_value {
         Import::Canister(canister_name) => {
             // duplicate code
             let path1 = format!("$(ROOT_DIR)/.dfx/local/canisters/{}/{}.wasm", canister_name, canister_name);
             let path2 = format!("$(ROOT_DIR)/.dfx/local/canisters/{}/{}.did", canister_name, canister_name);
             format!("{} {}", path1, path2)
         }
-        Import::FullPath(path) => format!("$(ROOT_DIR)/{}", path.to_str().unwrap().to_owned()), // FIXME: `unwrap`
+        Import::FullPath(path) => format!("$(ROOT_DIR)/{}", path.to_str().unwrap_or("<unknown>").to_owned()), // TODO: <unknown> is a hack
         Import::Ic(principal_str) => format!("ic:{}", principal_str),
         Import::Lib(_path) => "".to_string(),
-    }
+    })
 }
 
 fn get_build_command(graph: &Graph<Import, ()>, node_id: <Graph<Import, ()> as GraphBase>::NodeId) -> Option<String> {