fix: throwing repr caused a segfault (#2389)

* fix: throwing repr caused a segfault

* fixup! ci: include Python 3.9 RC1 (#2387)
diff --git a/tests/test_exceptions.cpp b/tests/test_exceptions.cpp
index 372d0ae..537819d 100644
--- a/tests/test_exceptions.cpp
+++ b/tests/test_exceptions.cpp
@@ -218,4 +218,7 @@
         }
     });
 
+    // Test repr that cannot be displayed
+    m.def("simple_bool_passthrough", [](bool x) {return x;});
+
 }