Qt-5 in core-updates

[Andreas Enge <andreas@enge.fr>]

Hello,

qt-5 fails to build on both x86_64 and armhf in core-updates with the
following error:
Traceback (most recent call last):
  File "/tmp/nix-build-qt-5.5.1.drv-0/qt-everywhere-opensource-src-5.5.1/qtwebkit/Source/WebKit2/Scripts/generate-messages-header.py", line 28, in <module>
    import webkit2.messages
EOFError: EOF read where object expected
Makefile.WebKit2.DerivedSources:881: recipe for target 'generated/PluginProxyMessages.h' failed
make[3]: *** [generated/PluginProxyMessages.h] Error 1

Surprisingly, it succeeds on i686 (and its build is disabled on mips).

宋文武, you appear to be the most knowledgeable among us concerning Qt;
could you maybe have look?

Thank you,

Andreas