Treat EXDEV as unsupported clonefile and handle possum_new error from Go

Author: anacrolix

go/handle.go

@@ -19,6 +19,10 @@ type Limits = possumC.Limits
 
 func Open(dir string) (handle *Handle, err error) {
 	cHandle := possumC.NewHandle(dir)
+	if cHandle == nil {
+		err = errors.New("unhandled possum error")
+		return
+	}
 	generics.InitNew(&handle)
 	handle.cHandle.Init(cHandle, func(cHandle *possumC.Handle) {
 		possumC.DropHandle(cHandle)

src/c_api/ext_fns/mod.rs

@@ -29,7 +29,7 @@ pub extern "C" fn possum_new(path: *const c_char) -> *mut PossumHandle {
     let handle = match Handle::new(path_buf.clone()) {
         Ok(handle) => handle,
         Err(err) => {
-            error!("error creating possum handle in {path_buf:?}: {err}");
+            error!("error creating possum handle in {path_buf:?}: {err:#?}");
             return null_mut();
         }
     };

src/dir.rs

@@ -37,8 +37,14 @@ impl Dir {
                 let _ = std::fs::remove_file(&dst_path);
                 match clone_res {
                     Ok(()) => true,
-                    Err(err) if CloneFileError::is_unsupported(&err) => false,
-                    Err(err) => return Err(err).context("testing clonefile"),
+                    Err(err) if CloneFileError::is_unsupported(&err) => {
+                        warn!(?err, "clonefile unsupported");
+                        false
+                    },
+                    Err(err) => {
+                        error!(?err);
+                        return Err(err).context("testing clonefile")
+                    },
                 }
             }
         };

src/handle.rs

@@ -103,7 +103,7 @@ impl Handle {
                 "3.42"
             );
         }
-        let dir = Dir::new(dir)?;
+        let dir = Dir::new(dir).context("new Dir")?;
         let mut conn = Connection::open(dir.path().join(MANIFEST_DB_FILE_NAME))?;
         Self::init_sqlite_conn(&mut conn, &dir)?;
         let (deleted_values, receiver) = sync::mpsc::sync_channel(10);

src/sys/clonefile/sys.rs

@@ -27,7 +27,7 @@ impl CloneFileError for NativeIoError {
     #[cfg(unix)]
     fn is_unsupported(&self) -> bool {
         self.raw_os_error()
-            .map(|errno| matches!(errno, EOPNOTSUPP))
+            .map(|errno| matches!(errno, EOPNOTSUPP | libc::EXDEV))
             .unwrap_or_default()
     }
     #[cfg(windows)]