fix: options with target

Author: kevindadi

README.md

@@ -17,5 +17,5 @@
    cargo install --path .
   ```
 3. Usage
-   `cargo pn -- -m datarace -t my-crate --type library --api-spec tests/lib.toml--viz-callgraph --viz-petrinet`
+   `cargo pn -- -m datarace -t my_crate --type library --api-spec tests/lib.toml--viz-callgraph --viz-petrinet`
 

src/options.rs

@@ -246,7 +246,10 @@ impl Options {
             _ => DetectorKind::Deadlock,
         };
 
-        self.crate_name = matches.get_one::<String>("target_crate").unwrap().clone();
+        self.crate_name = matches
+            .get_one::<String>("target_crate")
+            .expect("The target crate must be declared and linked with an underscore.")
+            .clone();
         self.output = matches
             .get_one::<String>("diagnostics_output")
             .cloned()