After install from the binary offline installer, I can't compile PyQt5.5.1 successfully, finally found that's because of :

1. there is no qgeolocation.h in 5.5/gcc_64/include/QtPositioning, which cause the compiling of QtPositioning module in PyQt5.5.1 failed.
I copied the 5.5/Src/qtlocation/src/positioning/qgeolocation.h into
5.5/gcc_64/include/QtPositioning, and then QtPositioning of PyQt5.5.1
compiled successfully.

2. the list of file names in 5.5/gcc_64/include/QtWebEngineWidgets
looks same with 5.5/Src/qtwebengine/include/QtWebEngineWidgets,
but the content of which is different.
This issue only cause the QtWebEigineWidgets module in PyQt5.5.1 compiled failed on my CentOS 6 system. when I recompile it on ArchLinux system, there is no wrong complained by the complier.

On CentOS6, If I override the files in 5.5/gcc_64/include/QtWebEngineWidgets with files in 5.5/Src/qtwebengine/include/QtWebEngineWidgets, all goes right.