I can see the light

src/common/file.rs

@@ -9,14 +9,14 @@ pub struct SrcFile {
     pub text: String,
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct FilePos {
     pub file: FileID,
     pub line: usize,
     pub col: usize,
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
 pub struct FileSpan {
     pub file: FileID,
     pub start: FilePos,

src/common/output.rs

@@ -19,7 +19,7 @@ impl CompilerMsg {
             spans: Vec::new(),
         }
     }
-    pub fn from_span(span: FileSpan, msg: String) -> Self {
+    pub fn new(msg: String, span: FileSpan) -> Self {
         Self {
             msg,
             spans: vec![span],