QMake install : bad copy command syntax

In QT Creator, after a library build, during deploy step I get this error:

copy /y C:/win32/Binx/libCpsFramework.so.debug C:\win32\UsrLib\build-CpsFramework-Android_for_armeabi_v7a_GCC_4_9_Qt_5_5_1-Release\android-build\libs\armeabi-v7a\libCpsFramework.so.debug
The syntax of the command is incorrect.
mingw32-make: [install_target] Error 1 (ignored)
makefile:15967: recipe for target 'install_target' failed

this is due to the fact that '/' is used instead of '\' because of Windows.
Path should be converted to native separators.

Build was done in release mode but with debug info.