Improve SQLPage function argument warnings

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## unreleased
  - OIDC protected and public paths now respect the site prefix when it is defined.
  - add submit and reset form button icons: validate_icon, reset_icon, reset_color
+ - improve error messages when sqlpage functions are used incorrectly. Include precise file reference and line number
 
 ## 0.42.0 (2026-01-17)
 

src/webserver/database/execute_queries.rs

@@ -331,6 +331,16 @@ fn debug_row(r: &AnyRow) {
 }
 
 fn clone_anyhow_err(source_file: &Path, err: &anyhow::Error) -> anyhow::Error {
+    if let Some(func_err) = err.downcast_ref::<super::sql::SqlPageFunctionError>() {
+        let line = func_err.line;
+        let loc = if line > 0 {
+            format!(":{line}")
+        } else {
+            String::new()
+        };
+        return anyhow::anyhow!("{}{loc} {}", source_file.display(), func_err);
+    }
+
     let mut e = anyhow!("{} contains a syntax error preventing SQLPage from parsing and preparing its SQL statements.", source_file.display());
     for c in err.chain().rev() {
         e = e.context(c.to_string());