[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."
--------------------------+----------------------
  Reporter:  wilya7       |      Owner:  ddennedy
      Type:  defect       |     Status:  assigned
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:
Resolution:               |   Keywords:
      Port:  mlt mlt-qt5  |
--------------------------+----------------------

Comment (by RJVB):

 Replying to [comment:17 ddennedy]:

 > libc++ is a part of LLVM, which is no longer bound to OS.

 Who said bound to? ;)
 I also have libc++ on Linux, but do you know any distribution that uses
 it? That's what I mean, you're still bound to the choice the OS made.

 > > What clang versions have "clang-9" in their version string? You'd need
 something that accounts for both the stock/official versioning (e.g.
 4.0.1) and Apple's sauce...
 >
 > On my 10.12.6 machine:
 > {{{
 > ddennedy-macbook:~ ddennedy$ clang++ --version
 > Apple LLVM version 9.0.0 (clang-900.0.38)
 > Target: x86_64-apple-darwin16.7.0
 > }}}
 > I have a OS X 10.8-based machine that I use for testing, and it says
 clang-8.... It did not work with the "-std=c++11" option when I added it
 to the Makefile and before I restricted it to gcc. However, it could have
 been that I needed to specify libc++ but did not. I will have to test that
 again.

 I have 10.9, and Xcode clang says `Apple LLVM version 6.0 (clang-600.0.57)
 (based on LLVM 3.5svn)`. That one still indicates the stock clang version
 it's based on. Then I have 2 other versions available:

 {{{
 > clang++-mp-3.9 --version ; clang++-mp-4.0 --version
 clang version 3.9.1 (tags/RELEASE_391/final)
 Target: x86_64-apple-darwin13.4.0
 Thread model: posix
 InstalledDir: /opt/local/libexec/llvm-3.9/bin
 clang version 4.0.1 (tags/RELEASE_401/final)
 Target: x86_64-apple-darwin13.4.0
 Thread model: posix
 InstalledDir: /opt/local/libexec/llvm-4.0/bin
 }}}

 your build system can run into any of those, and will have to figure out
 which is which...

--
Ticket URL: <https://trac.macports.org/ticket/54861#comment:18>
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