macports_version

[Andrew Moore]

> On May 20, 2018, at 9:45 PM, Ryan Schmidt <ryandesign at macports.org> wrote:
> 
> 
> On May 20, 2018, at 17:04, Andrew Moore wrote:
> 
>> On May 20, 2018, at 8:23 AM, Ryan Schmidt wrote:
>> 
>>> Why is macports_version a proc and not an option?
>> 
>> To make it read-only?  It seems procs and trace are Tcl’s way of defining constants.
> 
> Variables can be easily made read-only. We already have an xcode_version variable.

Are you referring to `macports::xcodeversion'? If so, this seems to be a trace'd variable tied
to a read command (macports.tcl:1185).