Okay. I tested and it appears to work if I shorten the path by substituting the long path with a drive letter.

subst k: x:\QMakeBased\Libraries\qwt-5.2.1

then

x:\32Bit\VC.90\Temp\Qwt-5.2.1>qmake -r k:\qwt.pro

then build and install..

Maybe I should bug microsoft for the reason why in 2010 we have a maximum command line length of 8K (or 8000?) in windows 7 64 bit.

But I guess that is a tremendous improvement over the past:
http://msdn.microsoft.com/en-us/libr...st(VS.80).aspx