The "haha" string is too likely to appear e.g. in /nix/store hashes.
--- a/tests/view_tests/tests/test_debug.py
+++ b/tests/view_tests/tests/test_debug.py
@@ -92 +92 @@
-            "file_data.txt": SimpleUploadedFile("file_data.txt", b"haha"),
+            "file_data.txt": SimpleUploadedFile("file_data.txt", b"hahaXGEENJAHSM"),
@@ -97 +97 @@
-        self.assertNotContains(response, "haha", status_code=500)
+        self.assertNotContains(response, "hahaXGEENJAHSM", status_code=500)