Mac: qmake.exe references build directory for QT_INSTALL_LIBEXECS

This is with package qt-mac-opensource-5.0.0-rc1-clang-offline-2012-12-03-362.dmg :

stenger@BtK-Mac-mini:~/Qt5.0.0-rc1 $ ./5.0.0-rc1/clang_64/bin/qmake -query
QT_SYSROOT:
QT_INSTALL_PREFIX:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64
QT_INSTALL_ARCHDATA:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64
QT_INSTALL_DATA:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/
QT_INSTALL_DOCS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/doc
QT_INSTALL_HEADERS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/include
QT_INSTALL_LIBS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/lib
QT_INSTALL_LIBEXECS:/Users/bld.qt/bamboo-agent-home/xml-data/build-dir/DQTC-RELEASE5LGPL-OSX106/_____________________________PADDING_____________________________/libexec
QT_INSTALL_BINS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/bin
QT_INSTALL_TESTS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/tests
QT_INSTALL_PLUGINS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/plugins
QT_INSTALL_IMPORTS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/imports
QT_INSTALL_QML:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/qml
QT_INSTALL_TRANSLATIONS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/translations
QT_INSTALL_CONFIGURATION:/Library/Preferences/Qt
QT_INSTALL_EXAMPLES:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/examples
QT_INSTALL_DEMOS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/examples
QT_HOST_PREFIX:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64
QT_HOST_DATA:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64
QT_HOST_BINS:/Users/stenger/Qt5.0.0-rc1/5.0.0-rc1/clang_64/bin
QMAKE_SPEC:macx-clang
QMAKE_XSPEC:macx-clang
QMAKE_VERSION:3.0
QT_VERSION:5.0.0