some observability

src/routes/pdf.rs

@@ -42,7 +42,7 @@ fn generate_pdf(browser: Browser) {
 }
 
 #[get("/cv/<username>/pdf")]
-pub async fn render_pdf_cv(username: &str, browser: BrowserHolder, tracing: TracingSpan) -> NamedFile { 
+pub async fn render_pdf_cv(username: &str, browser: BrowserHolder, tracing: TracingSpan) -> Option<NamedFile> { 
     let entered_span = tracing.0.enter();
     let span = info_span!("render_pdf", username = username);
     info!("generate PDF");
@@ -51,5 +51,5 @@ pub async fn render_pdf_cv(username: &str, browser: BrowserHolder, tracing: Trac
     });
     info!("done generating");
     drop(entered_span);
-    NamedFile::open("/tmp/foo.pdf").await.expect("failed to open foo.pdf")
+    Some(NamedFile::open("/tmp/foo.pdf").await.expect("failed to open foo.pdf"))
 }