[MacPorts] #57742: cairo @1.16.0 +quartz+universal+x11: cannot upgrade from @1.14.12 to @1.16.0

[MacPorts]

#57742: cairo @1.16.0 +quartz+universal+x11: cannot upgrade from @1.14.12 to
@1.16.0
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  Reporter:  hugo-ribeiro  |      Owner:  ryandesign
      Type:  defect        |     Status:  closed
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:  2.5.4
Resolution:  fixed         |   Keywords:  xcode10
      Port:  cairo         |
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Comment (by JDLH):

 Ken, thank you for the explanation about the cctools and ld64 variants.

 Which variants should I have installed?  Reading `port info cctools ld64`
 tells me the list of variants which exist, but as far as I can see, it
 doesn't describe the variants, or say which is the default variant, or
 recommend which one people should have installed.

 And where should I be reading to find out this sort of information? I
 appreciate you two taking the time to explain things in this ticket, but
 that form of user education doesn't scale.

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Ticket URL: <https://trac.macports.org/ticket/57742#comment:18>
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