passing -declarative-debug to configure fails

passing -declarative-debug to configure results in:

kimrhh@exherbo-work-laptop ~/git-repos/qt $ ./configure -declarative-debug
Which edition of Qt do you want to use ?

Type 'c' if you want to use the Commercial Edition.
Type 'o' if you want to use the Open Source Edition.

o

-declarative-debug: invalid command-line switch

Usage: configure [-h] [-prefix <dir>] [-prefix-install] [-bindir <dir>] [-libdir <dir>]
[-docdir <dir>] [-headerdir <dir>] [-plugindir <dir> ] [-importdir <dir>] [-datadir <dir>]
[-translationdir <dir>] [-sysconfdir <dir>] [-examplesdir <dir>]
[-demosdir <dir>] [-buildkey <key>] [-release] [-debug]
[-debug-and-release] [-developer-build] [-shared] [-static] [-no-fast] [-fast] [-no-largefile]
[-largefile] [-no-exceptions] [-exceptions] [-no-accessibility]
[-accessibility] [-no-stl] [-stl] [-no-sql-<driver>] [-sql-<driver>]
[-plugin-sql-<driver>] [-system-sqlite] [-no-qt3support] [-qt3support]
[-platform] [-D <string>] [-I <string>] [-L <string>] [-help]
[-qt-zlib] [-system-zlib] [-no-gif] [-qt-gif] [-no-libtiff] [-qt-libtiff] [-system-libtiff]
[-no-libpng] [-qt-libpng] [-system-libpng] [-no-libmng] [-qt-libmng]
[-system-libmng] [-no-libjpeg] [-qt-libjpeg] [-system-libjpeg] [-make <part>]
[-nomake <part>] [-R <string>] [-l <string>] [-no-rpath] [-rpath] [-continue]
[-verbose] [-v] [-silent] [-no-nis] [-nis] [-no-cups] [-cups] [-no-iconv]
[-iconv] [-no-pch] [-pch] [-no-dbus] [-dbus] [-dbus-linked] [-no-gui]
[-no-separate-debug-info] [-no-mmx] [-no-3dnow] [-no-sse] [-no-sse2]
[-no-sse3] [-no-ssse3] [-no-sse4.1] [-no-sse4.2] [-no-avx] [-no-neon]
[-qtnamespace <namespace>] [-qtlibinfix <infix>] [-separate-debug-info] [-armfpa]
[-no-optimized-qmake] [-optimized-qmake] [-no-xmlpatterns] [-xmlpatterns]
[-no-multimedia] [-multimedia] [-no-phonon] [-phonon] [-no-phonon-backend] [-phonon-backend]
[-no-media-backend] [-media-backend] [-no-audio-backend] [-audio-backend]
[-no-openssl] [-openssl] [-openssl-linked]
[-no-gtkstyle] [-gtkstyle] [-no-svg] [-svg] [-no-webkit] [-webkit] [-webkit-debug]
[-no-javascript-jit] [-javascript-jit]
[-no-script] [-script] [-no-scripttools] [-scripttools]
[-no-declarative] [-declarative][-no-declarative-debug] [-declarative-debug]
[additional platform specific options (see below)]

as it can be seen the option is listed.

I have attached a patch for 4.7.1 which makes it possible to enable that option.