Obviously you are trying to cross compile Qwt and you run into a command, where libraries from the host and target system are mixed up.
To find out what is going on I recommend to remove "CONFIG += silent" from qwtbuilt.pri - to see the failing command - and then to check which one ihe offending lib is.

By the way: I would also disable "QWT_CONFIG += QwtDesigner" in qwtconfig.pri too: guess you don't plan to run the creator on the target.

Uwe

PS: Qwt is supposed to run on any platform, where Qt is running