[MacPorts] #54861: mlt-qt5 install fails with the message "Package Qt5Core was not found in the pkg-config search path."

[MacPorts]

#54861: mlt-qt5 install fails with the message "Package Qt5Core was not found in
the pkg-config search path."
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  Reporter:  wilya7       |      Owner:  ddennedy
      Type:  defect       |     Status:  assigned
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:
Resolution:               |   Keywords:
      Port:  mlt mlt-qt5  |
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Comment (by wilya7):

 Replying to [comment:13 ddennedy]:
 > Regarding upstream, I have in my working copy a change to add
 "-std=c++11" when the c++ compiler contains clang-9 in its version string.
 >
 > The "-stdlib=libc++" part I am not so sure about as I have not had to
 make that change here. If you want that upstreaming - bearing in mind that
 the MLT Makeflle must be cross-platform and compatible with older versions
 of OSes and compilers - what sort of test would you suggest for including
 that?

 I understand. Unfortunately I have no idea how to be helpful here, besides
 thanking you again.

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Ticket URL: <https://trac.macports.org/ticket/54861#comment:14>
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