3 files changed, 10 insertions, 8 deletions
diff --git a/tvix/eval/src/builtins/impure.rs b/tvix/eval/src/builtins/impure.rs
index e01c642e0a4f..26d1ba494575 100644
--- a/tvix/eval/src/builtins/impure.rs
+++ b/tvix/eval/src/builtins/impure.rs
@@ -38,8 +38,10 @@ mod impure_builtins {
         let dir = generators::request_read_dir(&co, path).await;
         let res = dir.into_iter().map(|(name, ftype)| {
             (
-                // TODO: propagate Vec<u8> into NixString.
-                NixString::from(String::from_utf8(name).expect("parsing file name as string")),
+                // TODO: propagate Vec<u8> or bytes::Bytes into NixString.
+                NixString::from(
+                    String::from_utf8(name.to_vec()).expect("parsing file name as string"),
+                ),
                 Value::String(
                     match ftype {
                         FileType::Directory => "directory",
diff --git a/tvix/eval/src/io.rs b/tvix/eval/src/io.rs
index de3da9ebe8ec..1baa24439e4a 100644
--- a/tvix/eval/src/io.rs
+++ b/tvix/eval/src/io.rs
@@ -42,7 +42,7 @@ pub trait EvalIO {
 
     /// Read the directory at the specified path and return the names
     /// of its entries associated with their [`FileType`].
-    fn read_dir(&self, path: &Path) -> Result<Vec<(Vec<u8>, FileType)>, io::Error>;
+    fn read_dir(&self, path: &Path) -> Result<Vec<(bytes::Bytes, FileType)>, io::Error>;
 
     /// Import the given path. What this means depends on the
     /// implementation, for example for a `std::io`-based
@@ -76,7 +76,7 @@ impl EvalIO for StdIO {
         std::fs::read_to_string(&path)
     }
 
-    fn read_dir(&self, path: &Path) -> Result<Vec<(Vec<u8>, FileType)>, io::Error> {
+    fn read_dir(&self, path: &Path) -> Result<Vec<(bytes::Bytes, FileType)>, io::Error> {
         let mut result = vec![];
 
         for entry in path.read_dir()? {
@@ -93,7 +93,7 @@ impl EvalIO for StdIO {
                 FileType::Unknown
             };
 
-            result.push((entry.file_name().into_vec(), val))
+            result.push((entry.file_name().into_vec().into(), val))
         }
 
         Ok(result)
@@ -125,7 +125,7 @@ impl EvalIO for DummyIO {
         ))
     }
 
-    fn read_dir(&self, _: &Path) -> Result<Vec<(Vec<u8>, FileType)>, io::Error> {
+    fn read_dir(&self, _: &Path) -> Result<Vec<(bytes::Bytes, FileType)>, io::Error> {
         Err(io::Error::new(
             io::ErrorKind::Unsupported,
             "I/O methods are not implemented in DummyIO",
diff --git a/tvix/eval/src/vm/generators.rs b/tvix/eval/src/vm/generators.rs
index 3437136bde63..a195dac24f53 100644
--- a/tvix/eval/src/vm/generators.rs
+++ b/tvix/eval/src/vm/generators.rs
@@ -186,7 +186,7 @@ pub enum VMResponse {
     Path(PathBuf),
 
     /// VM response with the contents of a directory.
-    Directory(Vec<(Vec<u8>, FileType)>),
+    Directory(Vec<(bytes::Bytes, FileType)>),
 
     /// VM response with a span to use at the current point.
     Span(LightSpan),
@@ -735,7 +735,7 @@ pub(crate) async fn request_path_exists(co: &GenCo, path: PathBuf) -> Value {
     }
 }
 
-pub(crate) async fn request_read_dir(co: &GenCo, path: PathBuf) -> Vec<(Vec<u8>, FileType)> {
+pub(crate) async fn request_read_dir(co: &GenCo, path: PathBuf) -> Vec<(bytes::Bytes, FileType)> {
     match co.yield_(VMRequest::ReadDir(path)).await {
         VMResponse::Directory(dir) => dir,
         msg => panic!(