feat(tvix/eval): add error variant for runtime type errors r/4409

Change-Id: I74155cf01766b7a991a69522945bff67fbca5a16
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6073
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>

1 files changed, 6 insertions, 1 deletions

diff --git a/tvix/eval/src/errors.rs b/tvix/eval/src/errors.rs
index 14f6819862b1..3df51acb6ca6 100644
--- a/tvix/eval/src/errors.rs
+++ b/tvix/eval/src/errors.rs
@@ -1,7 +1,12 @@
 use std::fmt::Display;
 
 #[derive(Debug)]
-pub struct Error {}
+pub enum Error {
+    TypeError {
+        expected: &'static str,
+        actual: &'static str,
+    },
+}
 
 impl Display for Error {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {