cause a var fault with given msg argument, i.e., call variant_fault.cause msg, i.e., use the current variant_fault effect to fail with the given message.
0.095dev (2025-08-15 12:02:22 GIT hash 301b5b75e77076d091b38f555473f9f0e31e5b5c built by fridi@fzen)
msg, i.e., use the current variant_fault effect to fail with the given message.