Error when building Qt (fail on qtwebengine) with msvc 2015

[zeFresk]

Hello, sorry if I made any spelling mistakes, I'm french and I am not used to write in english.

Here's my problem : I am actually trying to build Qt 5.6 from source using msvc 2015 freshly installed.
I built the latest ICU version, all my environment variables look fine, all the dependencies are installed and set up correctly.
The build worked fine for 1 hour until the end of QtWebEngineCore :

I don't know why it fails like that. Of course I can skip qtwebengine but I would like to fix this.
I searched during an hour and found that moc.exe can fail if the directory contains non-standard characters, but it's not the case here... :/

X:\Programmation\MVS14\VC\BIN\nmake.exe -f Makefile.core_gyp_generator.Debug
	( if not exist Makefile.gyp_run X:\Programmation\msvc2015_32\qtbase\bin\qmake X:\Programmation\qt-src-5.6\qt-everywhere-opensource-src-5.6.0\qtwebengine\src\core\gyp_run.pro -o Makefile.gyp_run ) && X:\Programmation\MVS14\VC\BIN\nmake.exe -f Makefile.gyp_run
	X:\Programmation\MVS14\VC\BIN\nmake.exe -f Makefile.gyp_run.Debug all
	X:\Programmation\msvc2015_32\qtwebengine\src\3rdparty\ninja\ninja.exe  -C X:/Programmation/msvc2015_32/qtwebengine/src/core/Debug
ninja: Entering directory `X:/Programmation/msvc2015_32/qtwebengine/src/core/Debug'
[1/73] ACTION QtWebEngineCore: location_provider_qt.moc_77b3603f3e0b4538e38cc350a4bda9c0
[2/73] ACTION QtWebEngineCore: web_engine_settings.moc_77b3603f3e0b4538e38cc350a4bda9c0
FAILED: X:\Programmation\Python\python.exe gyp-win-tool action-wrapper environment.x86 QtWebEngineCore_target_web_engine_settings_moc_77b3603f3e0b4538e38cc350a4bda9c0..rsp x:/programmation/qt-src-5.6/qt-everywhere-opensource-src-5.6.0/qtwebengine\src\core
moc: Cannot open options file specified with @

QCommandLineParser: argument list cannot be empty, it should contain at least the executable name



FAILED: X:\Programmation\Python\python.exe gyp-win-tool action-wrapper environment.x86 QtWebEngineCore_target_location_provider_qt_moc_77b3603f3e0b4538e38cc350a4bda9c0..rsp x:/programmation/qt-src-5.6/qt-everywhere-opensource-src-5.6.0/qtwebengine\src\core
moc: Cannot open options file specified with @

QCommandLineParser: argument list cannot be empty, it should contain at least the executable name



ninja: build stopped: subcommand failed.

How can I fix this and finally build Qt please ?

Thank you for you help :)