Missing error message for composite operations

Heiko Braun reports:

I don't see any error details when composite op's fail.
Is it just me or a general problem?

Request
{
"operation" => "composite",
"address" => [],
"steps" => [

{ "operation" => "write-attribute", "address" => [ ("host" => "local"), ("server-config" => "server-one") ], "name" => "socket-binding-group", "value" => "standard-sockets" }

,

{ "operation" => "write-attribute", "address" => [ ("host" => "local"), ("server-config" => "server-one") ], "name" => "socket-binding-port-offset", "value" => 0 }

],
"child-type" => undefined
}

Response

Internal Server Error