[MacPorts] #55653: "sudo port upgrade outdated" fails

[MacPorts]

#55653: "sudo port upgrade outdated" fails
---------------------+-------------------
  Reporter:  jhi     |      Owner:
      Type:  defect  |     Status:  new
  Priority:  Normal  |  Milestone:
 Component:  base    |    Version:  2.4.2
Resolution:          |   Keywords:
      Port:          |
---------------------+-------------------

Comment (by ryandesign):

 Replying to [ticket:55653 jhi]:
 > {{{
 > $ sudo port upgrade outdated
 > Error: Follow https://guide.macports.org/#project.tickets to report a
 bug.
 > $
 > }}}
 >
 > And ... that's it.

 That could happen if there is a circular dependency in your outdated
 ports. MacPorts doesn't support circular dependencies, but sometimes they
 are accidentally introduced into the ports tree.

 What are your outdated ports?

 {{{
 port outdated
 }}}

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Ticket URL: <https://trac.macports.org/ticket/55653#comment:3>
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