restore 1.7 behavior on pandoc failure

Author: cscheid

news/changelog-1.8.md

@@ -16,6 +16,7 @@
 - ([#12657](https://github.com/quarto-dev/quarto-cli/pull/12657)): Load Giscus in generated script tag, to avoid wrong-theming in Chrome.
 - ([#12780](https://github.com/quarto-dev/quarto-cli/issues/12780)): `keep-ipynb: true` now works again correctly and intermediate `.quarto_ipynb` is not removed.
 - ([#13051](https://github.com/quarto-dev/quarto-cli/issues/13051)): Fixed support for captioned Markdown table inside Div syntax for crossref. This is special handling, but this could be output by function like `knitr::kable()` with old option support.
+- ([#13441](https://github.com/quarto-dev/quarto-cli/pull/13441)): Catch `undefined` exceptions in Pandoc failure to avoid spurious error message.
 
 ## Backwards-compatibility breaking changes
 

src/command/render/render-files.ts

@@ -352,12 +352,13 @@ export async function renderFiles(
     return await pandocRenderer.onComplete(false, options.flags?.quiet);
   } catch (error) {
     if (!(error instanceof Error)) {
-      warn("Should not have arrived here:", error);
-      throw error;
+      warn(`Error encountered when rendering files`);
     }
     return {
       files: (await pandocRenderer.onComplete(true)).files,
-      error: error || new Error(),
+      error: error instanceof Error
+        ? error
+        : new Error(error ? String(error) : undefined),
     };
   } finally {
     tempContext.cleanup();
@@ -409,12 +410,13 @@ export async function renderFile(
     return await pandocRenderer.onComplete(false, options.flags?.quiet);
   } catch (error) {
     if (!(error instanceof Error)) {
-      warn("Should not have arrived here:", error);
-      throw error;
+      warn(`Error encountered when rendering ${file.path}`);
     }
     return {
       files: (await pandocRenderer.onComplete(true)).files,
-      error: error || new Error(),
+      error: error instanceof Error
+        ? error
+        : new Error(error ? String(error) : undefined),
     };
   } finally {
     if (Deno.env.get("QUARTO_PROFILER_OUTPUT")) {