[MacPorts] #57613: port @ 2.5.4: diagnose command gives error about Xcode 10.1

[MacPorts]

#57613: port @ 2.5.4: diagnose command gives error about Xcode 10.1
-------------------------+--------------------
  Reporter:  hardingliu  |      Owner:  (none)
      Type:  defect      |     Status:  new
  Priority:  Normal      |  Milestone:
 Component:  base        |    Version:  2.5.99
Resolution:              |   Keywords:
      Port:              |
-------------------------+--------------------
Description changed by hardingliu:

Old description:

> "port diagnose" command gives:
> {{{
> Error: currently installed version of Xcode, 10.1, is not supported by
> MacPorts.  For your currently installed system, only the following
> versions of Xcode are supported:  10.0.
> }}}
>
> Xcode version: Version 10.1 (10B61)

New description:

 "port diagnose" command on macOS Mojave gives:
 {{{
 Error: currently installed version of Xcode, 10.1, is not supported by
 MacPorts.  For your currently installed system, only the following
 versions of Xcode are supported:  10.0.
 }}}

 Xcode version: Version 10.1 (10B61)

--

-- 
Ticket URL: <https://trac.macports.org/ticket/57613#comment:4>
MacPorts <https://www.macports.org/>
Ports system for macOS