Add graceful error handling to df script

manager/src/main.rs

@@ -2,15 +2,16 @@
 extern crate log;
 
 mod builder;
+mod error;
 mod linker;
 
 use builder::build_tree;
+use error::Errors;
 use linker::link_tree;
 use log::LevelFilter;
 use std::env;
 use std::path::PathBuf;
 use structopt::StructOpt;
-use tokio::io;
 
 #[derive(StructOpt)]
 struct Opt {
@@ -45,7 +46,14 @@ pub enum ColorMode {
 }
 
 #[tokio::main]
-async fn main() -> io::Result<()> {
+async fn main() {
+    match run().await {
+        Ok(_) => {}
+        Err(errors) => errors.log(),
+    }
+}
+
+async fn run() -> Result<(), Errors> {
     let opt = Opt::from_args();
 
     let filter_level = match opt.verbosity {