Cannot build Qt with gcc 5.1 on Windows 8.1.

[smallB]

I'm getting error msg:
zconf.h is missing.
After providing path to that file, in mkspec:

QMAKE_INCDIR            = "C:\qt5_5_0\qt-everywhere-opensource-src-5.5.0\qtbase\include\QtZlib"

QMAKE_INCDIR            = "C:\qt5_5_0\qt-everywhere-opensource-src-5.5.0\qtbase\include\QtZlib"

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it compiles but doesn't link, gives following error:

C:/qt5_5_0/qt-everywhere-opensource-src-5.5.0/qtbase/lib/libQt5Bootstrap.a(qbyte
array.o):qbytearray.cpp:(.text$_Z11qUncompressPKhi+0x8f): undefined reference to `z_uncompress'
C:/qt5_5_0/qt-everywhere-opensource-src-5.5.0/qtbase/lib/libQt5Bootstrap.a(qbytearray.o):qbytearray.cpp:(.text$_Z9qCompressPKhii+0xbb): undefined reference to `z_compress2'
collect2.exe: error: ld returned 1 exit status

C:/qt5_5_0/qt-everywhere-opensource-src-5.5.0/qtbase/lib/libQt5Bootstrap.a(qbyte
array.o):qbytearray.cpp:(.text$_Z11qUncompressPKhi+0x8f): undefined reference to `z_uncompress'
C:/qt5_5_0/qt-everywhere-opensource-src-5.5.0/qtbase/lib/libQt5Bootstrap.a(qbytearray.o):qbytearray.cpp:(.text$_Z9qCompressPKhii+0xbb): undefined reference to `z_compress2'
collect2.exe: error: ld returned 1 exit status

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Any ideas how to fix it so I can build it?
Another question, when will there be available QT build for windows build with GCC5.2?

Thank you.