1 files changed, 5 insertions, 0 deletions
diff --git a/tvix/eval/src/tests/tvix_tests/eval-fail-builtins-tojson-tostring-notcallable.nix b/tvix/eval/src/tests/tvix_tests/eval-fail-builtins-tojson-tostring-notcallable.nix
new file mode 100644
index 0000000000..345b76fde0
--- /dev/null
+++ b/tvix/eval/src/tests/tvix_tests/eval-fail-builtins-tojson-tostring-notcallable.nix
@@ -0,0 +1,5 @@
+# attribute sets with a non-callable `__toString` can not be
+# serialised to JSON.
+builtins.toJSON {
+  __toString = 42;
+}