emulator: imports work relatively to file being assembled (set cwd)

assembler/src/resolver.rs

@@ -66,7 +66,7 @@ fn generate_symbol_table(nodes: &[Node]) -> Result<HashMap<Symbol, u32>, Assembl
 }
 
 pub fn resolve_dependencies(mut nodes: Vec<Node>) -> Result<Vec<Node>, AssembleError> {
-    // first we get a list of imports
+    // First we get a list of imports.
     let mut dependencies = Vec::new();
     for node in &nodes {
         if let Opcode::Include = node.opcode() {
@@ -81,7 +81,11 @@ pub fn resolve_dependencies(mut nodes: Vec<Node>) -> Result<Vec<Node>, AssembleE
             } else {
                 unreachable!()
             };
-            let hash = quick_hash(&PathBuf::from(path).canonicalize().unwrap());
+            let hash = quick_hash(
+                &PathBuf::from(path)
+                    .canonicalize()
+                    .expect("ERROR: Invalid import path."),
+            );
 
             dependencies.push((name, hash));
         }