Merge pull request #9765 from thaJeztah/improve-error-message-3036

Improve error message for conflicting container name.

daemon/daemon.go

@@ -478,8 +478,8 @@ func (daemon *Daemon) reserveName(id, name string) (string, error) {
 		} else {
 			nameAsKnownByUser := strings.TrimPrefix(name, "/")
 			return "", fmt.Errorf(
-				"Conflict, The name %s is already assigned to %s. You have to delete (or rename) that container to be able to assign %s to a container again.", nameAsKnownByUser,
-				utils.TruncateID(conflictingContainer.ID), nameAsKnownByUser)
+				"Conflict. The name %q is already in use by container %s. You have to delete that container to be able to reuse that name.", nameAsKnownByUser,
+				utils.TruncateID(conflictingContainer.ID))
 		}
 	}
 	return name, nil