wdt: Assert that log collection basically worked

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/wdriver/wdriver.rs b/wdriver/wdriver.rs
index 8e3f0bfc6d627985201d1b0ffee4af9aee0a3b60..3bb661d6b59bba35dcd8101f9a945c8b5ef9b15c 100644 (file)
--- a/wdriver/wdriver.rs
+++ b/wdriver/wdriver.rs
@@ -410,6 +410,9 @@ impl<'g> WindowGuard<'g> {
           != Some(true)
       })
       .collect::<Result<Vec<String>,_>>()?;
+
+    assert!( ! log.is_empty() );
+
     log
   }