feat(tvix/castore): Fix build warnings in release mode r/7985

Fixes some build warnings that only happen when building in release mode
which disables `debug_assertions`.

Change-Id: I554d5fce7c869c23cf4aa93179f0ee9f7f7c834e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11490
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
Autosubmit: Connor Brewster <cbrewster@hey.com>
Reviewed-by: flokli <flokli@flokli.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/tvix/castore/src/directoryservice/closure_validator.rs b/tvix/castore/src/directoryservice/closure_validator.rs
index 461fc907bd..183928a86f 100644
--- a/tvix/castore/src/directoryservice/closure_validator.rs
+++ b/tvix/castore/src/directoryservice/closure_validator.rs
@@ -136,6 +136,7 @@ impl ClosureValidator {
         let mut visited_directory_count = 0;
         #[cfg(debug_assertions)]
         let mut visited_directory_ixs = HashSet::new();
+        #[cfg_attr(not(debug_assertions), allow(unused))]
         while let Some(directory_ix) = traversal.next(&self.graph) {
             #[cfg(debug_assertions)]
             visited_directory_ixs.insert(directory_ix);