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 (2026-02-20 12:42:29 GIT hash dbcc3e4b3d2a59f66230b482cff8f0b018178d77 built by fridi@fzen)
msg, i.e., use the current variant_fault effect to fail with the given message.