message: Included caught error message in the thrown Error message when attempting to load html import file.
diff: @@ -93,7 +93,7 @@ export async function inlineHtmlImport(
  dom5.nodeWalkAncestors(htmlImport, (node) => !node.parentNode)!;
  const body = dom5.query(document, matchers.body)!;
  const importSource = await loader(resolvedImportUrl).catch(err => {
  - throw new Error(`Unable to analyze ${resolvedImportUrl}`);
  + throw new Error(`Unable to load ${resolvedImportUrl}: ${err.message}`);
  });
  // Is there a better way to get what we want other than using
  