Investigate codex-bug 14146

codex-rs/utils/absolute-path/src/lib.rs

@@ -54,7 +54,14 @@ impl AbsolutePathBuf {
 
     pub fn from_absolute_path<P: AsRef<Path>>(path: P) -> std::io::Result<Self> {
         let expanded = Self::maybe_expand_home_directory(path.as_ref());
-        let absolute_path = expanded.absolutize()?;
+        let absolute_path = if expanded.is_absolute() {
+            // `path-absolutize` consults the process cwd in `absolutize()`, even
+            // for already-absolute paths. Keep absolute inputs independent from
+            // cwd so callers continue to work after the cwd disappears.
+            expanded.absolutize_from(Path::new("/"))?
+        } else {
+            expanded.absolutize()?
+        };
         Ok(Self(absolute_path.into_owned()))
     }
 

codex-rs/utils/absolute-path/tests/dead_cwd.rs

@@ -0,0 +1,43 @@
+use codex_utils_absolute_path::AbsolutePathBuf;
+use pretty_assertions::assert_eq;
+use std::io;
+use std::path::PathBuf;
+use tempfile::tempdir;
+
+struct CurrentDirGuard {
+    previous: PathBuf,
+}
+
+impl Drop for CurrentDirGuard {
+    fn drop(&mut self) {
+        std::env::set_current_dir(&self.previous).expect("restore cwd");
+    }
+}
+
+#[cfg(unix)]
+#[test]
+fn absolute_paths_still_resolve_when_current_dir_is_missing() -> io::Result<()> {
+    let target_root = tempdir()?;
+    let target_dir = target_root.path().join("target");
+    std::fs::create_dir(&target_dir)?;
+
+    let cwd_root = tempdir()?;
+    let cwd_dir = cwd_root.path().join("cwd");
+    std::fs::create_dir(&cwd_dir)?;
+
+    let _guard = CurrentDirGuard {
+        previous: std::env::current_dir()?,
+    };
+    std::env::set_current_dir(&cwd_dir)?;
+    std::fs::remove_dir(&cwd_dir)?;
+
+    assert_eq!(
+        std::env::current_dir().unwrap_err().kind(),
+        io::ErrorKind::NotFound
+    );
+
+    let target_path = target_dir.join("..").join("target");
+    let resolved = AbsolutePathBuf::from_absolute_path(&target_path)?;
+    assert_eq!(resolved.as_path(), target_dir.as_path());
+    Ok(())
+}