Wrong error message for not-existing module behind mount point

GET http://localhost:8181/restconf/config/network-topology:network-topology/topology/topology-netconf/node/device1/yang-ext:mount/not-existing-module:container-a

Response:
{
"errors": {
"error": [

{ "error-type": "protocol", "error-tag": "unknown-element", "error-message": "\"yang-ext\" module does not exist in mount point." }

]
}
}

but better is:
"error-message": "The module named 'not-existing-module' does not exist in mount point."

[ControllerContext:567, 592]