[MacPorts] #55393: graphviz +rsvg depends on graphviz; circular dependency; prevents installation

[MacPorts]

#55393: graphviz +rsvg depends on graphviz; circular dependency; prevents
installation
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  Reporter:  rhstanton  |      Owner:  ryandesign
      Type:  defect     |     Status:  assigned
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:
Resolution:             |   Keywords:
      Port:  graphviz   |
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Comment (by cooljeanius):

 Note that this also makes it difficult to switch variants if one variant
 (say, `+smyrna`) has a build error and needs to be deselected for the
 version upgrade to complete

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Ticket URL: <https://trac.macports.org/ticket/55393#comment:14>
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