[MacPorts] #65269: mpi portgroup fails to select a C compiler variant if the default is disallowed

[MacPorts]

#65269: mpi portgroup fails to select a C compiler variant if the default is
disallowed
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  Reporter:  jmroot  |      Owner:  mascguy
      Type:  defect  |     Status:  assigned
  Priority:  Normal  |  Milestone:
 Component:  ports   |    Version:
Resolution:          |   Keywords:
      Port:          |
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Comment (by mascguy):

 Replying to [comment:9 jmroot]:
 > Or you could pick a default variant to use when the user hasn't chosen
 one and the default configure.compiler doesn't match one.

 Sounds reasonable, though I could use some guidance relative to the
 heuristics: Given the intricacies of compiler selection and such - and how
 easy it would be to break all of our MPI-dependent ports - I'd definitely
 want to collaborate via a PR as well. (Perhaps I'm over-thinking this, but
 better to be safe...)

-- 
Ticket URL: <https://trac.macports.org/ticket/65269#comment:10>
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