Linker mess in Qt after VS2015 install

I had to install VS2015 in the same machine I am working with Qt+oF.
For VS I had a separate oF folder since oF is compiled differently for VS, so there should be no conflicts between VS and Qt.
But actually if now I try to build an oF project in QT I get a ton of error messages from the linker, most of them are from Poco library. Here are some lines:

C:/of_v0.9.8/libs/poco/lib/msys2/libPocoNetSSL.a(HTTPSClientSession.o): duplicate section .rdata$_ZTIN4Poco3Net4Impl17SocketAddressImplE[__ZTIN4Poco3Net4Impl17SocketAddressImplE]' has different size C:/of_v0.9.8/libs/poco/lib/msys2/libPocoNetSSL.a(HTTPSClientSession.o): duplicate section.rdata$_ZTVN4Poco3Net4Impl21IPv4SocketAddressImplE[__ZTVN4Poco3Net4Impl21IPv4SocketAddressImplE]’ has different size
C:/of_v0.9.8/libs/poco/lib/msys2/libPocoNetSSL.a(HTTPSClientSession.o): duplicate section .rdata$_ZTVN4Poco3Net4Impl21IPv6SocketAddressImplE[__ZTVN4Poco3Net4Impl21IPv6SocketAddressImplE]' has different size C:/of_v0.9.8/libs/poco/lib/msys2/libPocoNetSSL.a(HTTPSStreamFactory.o): duplicate section.rdata$_ZTIN4Poco3Net4Impl17SocketAddressImplE[__ZTIN4Poco3Net4Impl17SocketAddressImplE]’ has different size

I also get some FIND errors at the start of build:

building openFrameworks library
c:\msys64\usr\bin/make.exe -j4 Debug
FIND: formato del parametro non corretto
FIND: formato del parametro non corretto
FIND: formato del parametro non corretto
HOST_OS=MSYS_NT-10.0
checking pkg-config libraries: cairo zlib openssl glew
HOST_OS=MSYS_NT-10.0
checking pkg-config libraries: cairo zlib openssl glew
HOST_OS=MSYS_NT-10.0
checking pkg-config libraries: cairo zlib openssl glew
Done!

“formato del parametro non corretto” means “parameter format is wrong”.

Anyway, if i build the project from the command line of msys2 everything works fine.

Anyone knows what’s happening?..

related to Linker errors with of_v0.9.8 + QtCreator 4.1