[MacPorts] #72606: graphviz @12.2.1 failed to configure on M3 Sonoma 14.7.6

[MacPorts]

#72606: graphviz @12.2.1 failed to configure on M3 Sonoma 14.7.6
------------------------+------------------------
  Reporter:  Fr1tigern  |      Owner:  ryandesign
      Type:  defect     |     Status:  assigned
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:  2.10.7
Resolution:             |   Keywords:
      Port:  graphviz   |
------------------------+------------------------

Comment (by Fr1tigern):

 Thank you for this excellent reply. I will follow the trail to the ticket
 referred,
 In answer to the question following realisation that macPorts was using
 the wrong compiler for its eighth attempt to compile, I did not knowingly
 manually override the use of the normal C++ compiler, not by Terminal
 command anyway. This was the first time I have used macPorts in 20 years
 of using a Mac as my principal home computer. It started with me trying to
 install home-brew to download and install mosquitto, an attempt that
 failed, so I did what I should have at the start- updated xCode and
 installed Rosetta2. Homebrew sill would not load so I tried using macPorts
 to install mosquitto instead. With multiple apparant  failures and some
 not very effective help from Google I did change Terminal to "open using
 Rosetta". I'm sure I tried to do the macports rev-upgrade more than once
 after this, so Rosetta can't be to blame, especially as I have just
 restored Terminal to not using Rosetta and had the ubiquitous fail to
 configure graphviz. This is unbelievably frustrating as there is no
 relevant or reliable help on the internet. The apple forum is full of
 people making fatuous remarks just to increase their score of "replies".
 And I'll try the solution suggested. Thanks

-- 
Ticket URL: <https://trac.macports.org/ticket/72606#comment:6>
MacPorts <https://www.macports.org/>
Ports system for macOS