fix: rendering in typst

src/export/typst.rs

@@ -69,6 +69,7 @@ use crate::Layout;
 use crate::assessment::{AssessmentFile, Form};
 use crate::catalog::Catalog;
 use crate::error::{Error, Result};
+use crate::markup;
 
 /// What to render.
 #[derive(Debug, Clone)]
@@ -195,6 +196,17 @@ pub fn render(catalog: &Catalog, record: &AssessmentFile, opts: &Options) -> Res
     }
 
     let mut warnings = payload::check(&payload, &opts.config);
+    for (slot, body) in &bodies {
+        if markup::needs_chem_import(&template.source, body) {
+            warnings.push(format!(
+                "the `{}` slot carries a chemical formula, but the template {} does not import \
+                 whalogen, so Typst will stop at `unknown variable: ce`; add `{}`",
+                slot.as_str(),
+                template.origin,
+                markup::CHEM_IMPORT
+            ));
+        }
+    }
     if template.is_inert() {
         warnings.push(format!(
             "the template {} declares no coursebank markers, so no questions were injected; add \