.

go/neo/neonet/connection.go

-// Copyright (C) 2016-2018  Nexedi SA and Contributors.
+// Copyright (C) 2016-2020  Nexedi SA and Contributors.
 //                          Kirill Smelkov <kirr@nexedi.com>
 //
 // This program is free software: you can Use, Study, Modify and Redistribute
@@ -1284,7 +1284,9 @@ func (e *ConnError) Error() string {
 }
 
 func (e *LinkError) Cause()  error { return e.Err }
+func (e *LinkError) Unwrap() error { return e.Err }
 func (e *ConnError) Cause()  error { return e.Err }
+func (e *ConnError) Unwrap() error { return e.Err }
 
 func (nl *NodeLink) err(op string, e error) error {
 	if e == nil {

go/zodb/storage/fs1/format.go

-// Copyright (C) 2017-2019  Nexedi SA and Contributors.
+// Copyright (C) 2017-2020  Nexedi SA and Contributors.
 //                          Kirill Smelkov <kirr@nexedi.com>
 //
 // This program is free software: you can Use, Study, Modify and Redistribute
@@ -97,9 +97,8 @@ type RecordError struct {
 	Err    error  // actual error
 }
 
-func (e *RecordError) Cause() error {
-	return e.Err
-}
+func (e *RecordError) Cause() error  { return e.Err }
+func (e *RecordError) Unwrap() error { return e.Err }
 
 func (e *RecordError) Error() string {
 	// XXX omit path: when .Err already contains it (e.g. when it is os.PathError)?

go/zodb/zodb.go

-// Copyright (C) 2016-2019  Nexedi SA and Contributors.
+// Copyright (C) 2016-2020  Nexedi SA and Contributors.
 //                          Kirill Smelkov <kirr@nexedi.com>
 //
 // This program is free software: you can Use, Study, Modify and Redistribute
@@ -316,9 +316,8 @@ func (e *OpError) Error() string {
 	return s
 }
 
-func (e *OpError) Cause() error {
-	return e.Err
-}
+func (e *OpError) Cause() error  { return e.Err }
+func (e *OpError) Unwrap() error { return e.Err }
 
 
 // IStorage is the interface provided by opened ZODB storage.