context: copy symlinks as symlinks and improve error messages

src/context/unshare.rs

@@ -1,6 +1,8 @@
 use super::api::{Context, ContextCommand, ContextDriver};
 use log::debug;
+use std::fs;
 use std::io;
+use std::os::unix::fs::symlink;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
@@ -9,23 +11,88 @@ pub struct UnshareDriver {
     pub parent: Option<Arc<super::api::Context>>,
 }
 
-/// Recursively copy a directory and all its contents
+/// Recursively copy a directory and all its contents.
+///
+/// Symlinks are copied as symlinks (preserving the link target rather than
+/// following it), so that dangling links do not abort the copy.
 fn copy_dir_recursive(src: &Path, dest: &Path) -> io::Result<()> {
     // Create the destination directory
-    std::fs::create_dir_all(dest)?;
+    std::fs::create_dir_all(dest).map_err(|e| {
+        io::Error::new(
+            e.kind(),
+            format!("Failed to create directory '{}': {}", dest.display(), e),
+        )
+    })?;
 
     // Iterate through the source directory
-    for entry in std::fs::read_dir(src)? {
-        let entry = entry?;
+    let read = std::fs::read_dir(src).map_err(|e| {
+        io::Error::new(
+            e.kind(),
+            format!("Failed to read directory '{}': {}", src.display(), e),
+        )
+    })?;
+    for entry in read {
+        let entry = entry.map_err(|e| {
+            io::Error::new(
+                e.kind(),
+                format!("Failed to read entry in '{}': {}", src.display(), e),
+            )
+        })?;
         let src_path = entry.path();
         let dest_path = dest.join(entry.file_name());
 
-        if src_path.is_dir() {
+        // Handle symlinks explicitly: reproduce the link itself instead of
+        // following it. This avoids failing on dangling/absolute symlinks.
+        let metadata = match std::fs::symlink_metadata(&src_path) {
+            Ok(m) => m,
+            Err(e) => {
+                return Err(io::Error::new(
+                    e.kind(),
+                    format!(
+                        "Failed to read metadata of '{}': {}",
+                        src_path.display(),
+                        e
+                    ),
+                ))
+            }
+        };
+
+        if metadata.file_type().is_symlink() {
+            let target = std::fs::read_link(&src_path).map_err(|e| {
+                io::Error::new(
+                    e.kind(),
+                    format!("Failed to read symlink '{}': {}", src_path.display(), e),
+                )
+            })?;
+            // Remove an existing destination entry (e.g. from a previous attempt)
+            let _ = fs::remove_file(&dest_path);
+            symlink(&target, &dest_path).map_err(|e| {
+                io::Error::new(
+                    e.kind(),
+                    format!(
+                        "Failed to create symlink '{}' -> '{}': {}",
+                        dest_path.display(),
+                        target.display(),
+                        e
+                    ),
+                )
+            })?;
+        } else if src_path.is_dir() {
             // Recursively copy subdirectories
             copy_dir_recursive(&src_path, &dest_path)?;
         } else {
-            // Copy files
-            std::fs::copy(&src_path, &dest_path)?;
+            // Copy regular files
+            std::fs::copy(&src_path, &dest_path).map_err(|e| {
+                io::Error::new(
+                    e.kind(),
+                    format!(
+                        "Failed to copy '{}' to '{}': {}",
+                        src_path.display(),
+                        dest_path.display(),
+                        e
+                    ),
+                )
+            })?;
         }
     }