"This version of Mac OS X is unsupported"

Mac OS X 10.7.1, XCode 4.1

Compiling and linking against QT4 libraries produces the following
warning

In file included from /Library/Frameworks/QtCore.framework/Headers/qchar.h:45,
from /Library/Frameworks/QtCore.framework/Headers/qstring.h:45,
from /Library/Frameworks/QtXml.framework/Versions/4/Headers/qdom.h:45,
from /Library/Frameworks/QtXml.framework/Versions/4/Headers/QDomDocument:1,
from ../XMLTree/XMLDomTreeBuilder.h:8,
from ../XMLTree/XMLTree.h:4,
from ./GrowthLoop.h:20,
from pine.cc:2:
/Library/Frameworks/QtCore.framework/Headers/qglobal.h:320:6: warning: #warning "This version of Mac OS X is unsupported"