how to uninstall macport with OS conflict ?

[Ryan Schmidt]

> On May 19, 2017, at 04:13, db <iamsudo at gmail.com> wrote:
> 
>> On 19 May 2017, at 00:00, Clemens Lang <cal at macports.org> wrote:
>> Run the MacPorts installer for your new OS (yes, I know it's counter-intuitive), then follow the uninstall instructions. It should only take a couple of minutes if you use the installer and allow for clean removal even if you had ports installed that install files outside of /opt/local.
> 
> I still haven't had this problem, but does running the installer for the current OS version uninstall the previous base and ports _and_ reinstall the requested ports?

No. It installs the base files, and port "database", overwriting any that might already be there. It does nothing to your installed ports. 

> If not, as I presume, shouldn't it be an option?

Any number of problems can occur while installing ports. The user needs to be in a position to see error messages, access log files, retry an installation. The installer is not a good environment for that to occur in. The user needs to do it in the terminal.