[MacPorts] #66852: cairo, cairo-devel: Update to 1.18.0

[MacPorts]

#66852: cairo, cairo-devel: Update to 1.18.0
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  Reporter:  ryandesign         |      Owner:  mascguy
      Type:  update             |     Status:  assigned
  Priority:  Normal             |  Milestone:
 Component:  ports              |    Version:  2.8.1
Resolution:                     |   Keywords:
      Port:  cairo cairo-devel  |
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Comment (by mascguy):

 Replying to [comment:19 mascguy]:
 > For everyone's awareness: Given the test failures that Ken and I are
 seeing, it makes sense to run through some further Cairo-specific
 validation.
 >
 > So I'll go ahead and test with some of upstream's sample apps, for
 another point of reference:
 >
 > https://gitlab.com/cairo/cairo-demos

 Finally had a chance to circle back to `cairo-demos`. But it may take a
 bit of work to modify the various Makefiles and such, to correctly build.

 Ultimately it might be easiest to simply add them to `cairo-devel`,
 perhaps via a new variant like 'demos'. (Or include them as part of
 variant 'tests`?)

-- 
Ticket URL: <https://trac.macports.org/ticket/66852#comment:20>
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