[提问]qmake问题 [复制链接]

qmake 如下，运行后显示错误：Error while building project undo (target: Desktop)
When executing build step 'qmake'求大侠指点！
SOURCES += main.cpp mainwindow.cpp commands.cpp document.cpp \
    qirrwidget.cpp
HEADERS += mainwindow.h commands.h document.h \
    qirrwidget.h
FORMS += mainwindow.ui

LIBS += -LD:/irrlicht-1.7.2/lib/Win32-gcc -lIrrlicht
INCLUDEPATH +=  D:/irrlicht-1.7.2/include


build_all:!build_pass {
    CONFIG -= build_all
    CONFIG += release
}
RESOURCES += undo.qrc


# install
target.path = $$[QT_INSTALL_DEMOS]/undo/Debug
sources.files = $$SOURCES $$HEADERS *.pro icons $$RESOURCES $$FORMS
sources.path = $$[QT_INSTALL_DEMOS]/undo
INSTALLS += target sources

symbian: include($$QT_SOURCE_TREE/demos/symbianpkgrules.pri)

问题已解决：
When you open an existing project file (e.g. ProjectName.pro) the first time you may get the following error message:

Error while building project ProjectName (target: Desktop)
When executing build step ‘qmake’

The most likely cause of this is that the build settings are invalid or missing. In Qt Creator click Projects on the left side. The Build Settings page will be displayed. In the field Edit build configuration enter the configuration you like to use (e.g. Qt 4.7.4 for Desktop – MSVC2008 (Qt SDK) Debug).