[MacPorts] #56398: libvpx @1.7.0: Toolchain is unable to link executables (was: MacOS 10.13.4 : installing ffmpeg failure with libvpx)

[MacPorts]

#56398: libvpx @1.7.0: Toolchain is unable to link executables
----------------------+----------------------
  Reporter:  cgilles  |      Owner:  dbevans
      Type:  defect   |     Status:  assigned
  Priority:  Normal   |  Milestone:
 Component:  ports    |    Version:
Resolution:           |   Keywords:
      Port:  libvpx   |
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Comment (by ryandesign):

 Ok, the main.log is fairly straightforward about what the problem is:

 > {{{
 > Toolchain is unable to link executables
 > }}}

 And config.log shows us why:

 > {{{
 > ld: unexpected token: !tapi-tbd-v2 file
 '/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk/usr/lib/libpthread.tbd'
 for architecture x86_64
 > }}}

 It shows the MacPorts clang 3.9 compiler being used, together with the
 10.13 SDK. That's probably not going to work; the 10.13 SDK requires a
 current version of clang. Older versions of clang can't understand the
 text-based dependency (.tbd) format used in newer SDKs. Why is it using
 such an old version of clang? What version of clang is /usr/bin/clang?
 What version of Xcode is installed?

 I also see reference to `MACOSX_DEPLOYMENT_TARGET` being set to `10.8`. I
 assume you've done that deliberately by editing macports.conf. That by
 itself shouldn't be a problem.

-- 
Ticket URL: <https://trac.macports.org/ticket/56398#comment:2>
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