In case when module attribute from Elytron dir-context includes module which does not exist, then insufficient failure description is provided - it only prints name of given module. It should rather inform that given module does not exist.

See:

/subsystem=elytron/dir-context=someDirContext:add(url=localhost,module=wrong.module)
{
    "outcome" => "failed",
    "failure-description" => "wrong.module",
    "rolled-back" => true
}