kdesrc-build stops at phonon-gstreamer

In the archbase docker container (that's created running sudo ./run.py --base archlinux) when I run sudo ./kdesrc-build/kdesrc-build I get all the way to this part where is stops:

Building phonon-gstreamer from phonon (65/222)
    Updating phonon-gstreamer (to branch master)
    No source update, but the last configure failed
    Source update complete for phonon-gstreamer: no files affected
    Preparing build system for phonon-gstreamer.
    Removing files in build directory for phonon-gstreamer
    Old build system cleaned, starting new build system.
    Running cmake...
    Unable to configure phonon-gstreamer with CMake!
    Unable to configure phonon-gstreamer with KDE

phonon-gstreamer didn't build, stopping here.
Removing 5 out of 6 old log directories...

<<<  PACKAGES FAILED TO BUILD  >>>
phonon-gstreamer - /work/source/log/2015-09-27-06/phonon-gstreamer/cmake.log
:-(
Your logs are saved in /work/source/log/2015-09-27-06
[kdedev@8e5590b73373 ~]$

Looking at the cmake.log

[kdedev@8e5590b73373 ~]$ cat /work/source/log/2015-09-27-06/phonon-gstreamer/cmake.log
# kdesrc-build running: 'cmake' '/work/source/kdesupport/phonon/phonon-gstreamer' '-DBUILD_TESTING=TRUE' '-DCMAKE_BUILD_TYPE=Debug' '-DCMAKE_INSTALL_LIBDIR=lib' '-DLIB_SUFFIX=64' '-DPHONON_BUILD_PHONON4QT5=ON' '-DCMAKE_CXX_FLAGS:STRING=-pipe -DQT_STRICT_ITERATORS -DQURL_NO_CAST_FROM_STRING -DQT_NO_HTTP -DQT_NO_FTP -Wformat -Werror=return-type -Wno-variadic-macros -Wlogical-op ' '-DCMAKE_INSTALL_PREFIX=/work/install'
# from directory: /work/build/kdesupport/phonon/phonon-gstreamer
-- The C compiler identification is GNU 5.2.0
-- The CXX compiler identification is GNU 5.2.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Looking for __GLIBC__
-- Looking for __GLIBC__ - found
-- Performing Test _OFFT_IS_64BIT
-- Performing Test _OFFT_IS_64BIT - Success
-- Using CMake automoc builtin
-- Found Phonon4Qt5: /work/install/lib/cmake/phonon4qt5
-- Found OpenGL: /usr/lib64/libGL.so  
-- Found PkgConfig: /usr/bin/pkg-config (found version "0.28") 
-- checking for module 'gstreamer-1.0'
--   found gstreamer-1.0, version 1.4.5
-- Found GStreamer: /usr/lib64/libgstreamer-1.0.so
-- checking for module 'gstreamer-plugins-base-1.0'
--   found gstreamer-plugins-base-1.0, version 1.4.5
-- checking for module 'gstreamer-audio-1.0'
--   found gstreamer-audio-1.0, version 1.4.5
-- checking for module 'gstreamer-cdda-1.0'
--   package 'gstreamer-cdda-1.0' not found
-- Could not find cdda plugin
-- CDDA library: 
-- CDDA include dir: 
-- checking for module 'gstreamer-netbuffer-1.0'
--   package 'gstreamer-netbuffer-1.0' not found
-- Could not find netbuffer plugin
-- NETBUFFER library: 
-- NETBUFFER include dir: 
-- checking for module 'gstreamer-pbutils-1.0'
--   found gstreamer-pbutils-1.0, version 1.4.5
-- checking for module 'gstreamer-riff-1.0'
--   found gstreamer-riff-1.0, version 1.4.5
-- checking for module 'gstreamer-rtp-1.0'
--   found gstreamer-rtp-1.0, version 1.4.5
-- checking for module 'gstreamer-rtsp-1.0'
--   found gstreamer-rtsp-1.0, version 1.4.5
-- checking for module 'gstreamer-sdp-1.0'
--   found gstreamer-sdp-1.0, version 1.4.5
-- checking for module 'gstreamer-tag-1.0'
--   found gstreamer-tag-1.0, version 1.4.5
-- checking for module 'gstreamer-video-1.0'
--   found gstreamer-video-1.0, version 1.4.5
-- checking for module 'glib-2.0'
--   found glib-2.0, version 2.44.1
-- Found GLIB2: /usr/lib64/libglib-2.0.so
-- checking for module 'gobject-2.0'
--   found gobject-2.0, version 2.44.1
-- Found GOBJECT: /usr/lib64/libgobject-2.0.so;/usr/lib64/libgmodule-2.0.so;/usr/lib64/libgthread-2.0.so;/usr/lib64/libglib-2.0.so
-- Found LibXml2: /usr/lib64/libxml2.so (found version "2.9.2") 
-- Building against Phonon 4.7 API
CMake Error at /usr/lib64/cmake/Qt5Core/Qt5CoreMacros.cmake:310 (message):
  The first argument to qt5_use_modules must be an existing target.
Call Stack (most recent call first):
  gstreamer/CMakeLists.txt:96 (qt5_use_modules)

-- Configuring incomplete, errors occurred!
See also "/work/build/kdesupport/phonon/phonon-gstreamer/CMakeFiles/CMakeOutput.log".
[kdedev@8e5590b73373 ~]$

This is the part of the gstreamer/CMakeLists.txt file it's talking about:

if(Qt5X11Extras_FOUND)
  set(phonon_gstreamer_SRCS
      ${phonon_gstreamer_SRCS}
      x11renderer.cpp)
  add_definitions(-DHAVE_X11)
  qt5_use_modules(phonon_gstreamer X11Extras)
  target_link_libraries(phonon_gstreamer Qt5::X11Extras)
endif(Qt5X11Extras_FOUND)

Wenzel / docker-kdesrc-build

kdesrc-build stops at phonon-gstreamer #10