Fix unit tests (and fail miserably)
diff --git a/go/pkg/client/cas_test.go b/go/pkg/client/cas_test.go
index 6381a4c..f1bbc7a 100644
--- a/go/pkg/client/cas_test.go
+++ b/go/pkg/client/cas_test.go
@@ -686,8 +686,8 @@
 			for i := 0; i < 50; i++ {
 				eg.Go(func() error {
 					// Verify that we got a context cancellation error. Sometimes, the request can succeed, if the original thread takes a while to run.
-					if _, _, err := c.UploadIfMissing(cCtx, input...); err != nil && !errors.Is(err, context.Canceled) {
-						return fmt.Errorf("c.UploadIfMissing(ctx, input) gave error %v, expected context canceled", err)
+					if _, _, err := c.UploadIfMissing(cCtx, input...); err != nil && status.FromContextError(err).Code() != codes.Canceled {
+						return fmt.Errorf("c.UploadIfMissing(ctx, input) gave error %v (Code %v), expected context canceled", err, status.FromContextError(err).Code())
 					}
 					return nil
 				})