Add result check in main

src/main.rs

@@ -49,7 +49,23 @@ fn main() -> Result<()> {
         .get_matches();
 
     let config = matches.value_of("config").unwrap_or("~/.taskrc");
-    task::block_on(tui_main(config))
+    let r = task::block_on(tui_main(config));
+    match r {
+        Ok(_) => std::process::exit(0),
+        Err(error) => {
+            if error.to_string().to_lowercase().contains("no such file or directory") {
+                eprintln!(
+                    "[taskwarrior-tui error]: Unable to find executable `task`: {}. Check that taskwarrior is installed correctly and try again.", error
+                );
+            } else {
+                eprintln!(
+                    "[taskwarrior-tui error]: {}. Please report as a github issue on https://github.com/kdheepak/taskwarrior-tui",
+                    error
+                );
+            }
+            std::process::exit(1);
+        }
+    }
 }
 
 async fn tui_main(_config: &str) -> Result<()> {