From b83723a1edef90e4020b9b9af6c905d2badbedea Mon Sep 17 00:00:00 2001
From: Vincent Ambo <mail@tazj.in>
Date: Fri, 2 Sep 2022 23:46:06 +0300
Subject: fix(tvix/eval): force argument of builtins.length

Change-Id: Iaf94dfc7cb058f5c1c311066d92e01512e09cf71
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6417
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
---
 tvix/eval/src/builtins/mod.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'tvix')

diff --git a/tvix/eval/src/builtins/mod.rs b/tvix/eval/src/builtins/mod.rs
index d0ed834a9e2c..947854e6f00a 100644
--- a/tvix/eval/src/builtins/mod.rs
+++ b/tvix/eval/src/builtins/mod.rs
@@ -45,7 +45,10 @@ fn pure_builtins() -> Vec<Builtin> {
             let a = args.pop().unwrap();
             arithmetic_op!(a, b, /)
         }),
-        Builtin::new("length", 1, |args, _| {
+        Builtin::new("length", 1, |args, vm| {
+            if let Value::Thunk(t) = &args[0] {
+                t.force(vm)?;
+            }
             Ok(Value::Integer(args[0].to_list()?.len() as i64))
         }),
         Builtin::new("isAttrs", 1, |args, _| {
-- 
cgit 1.4.1