LSB build using linux-lsb-g++ mkspec fails on 64-bit (wrong library search path used)

When using the linux-lsb-g++ mkspec to build Qt 4.7.0, it currently fails with the following error:

lsbc++ -Wl,-rpath-link,/mypath/qt-everywhere-opensource-src-4.7.0/lib --lsb-libpath=/mypath/qt-everywhere-opensource-src-4.7.0/lib -L/opt/lsb/lib --lsb-shared-libs=QtCore -shared -Wl,-soname,libQtXml.so.4 -o libQtXml.so.4.7.0 .obj/release-shared/qdom.o .obj/release-shared/qxml.o -L/mypath/qt-everywhere-opensource-src-4.7.0/lib -lQtCore -L/mypath/qt-everywhere-opensource-src-4.7.0/lib -lpthread
/usr/bin/ld: cannot find -lgcc34compat

The thing to note here is that the library search path is listed as -L/opt/lsb/lib but with the latest 4.0 LSB build packages, this path does not exist on 64-bit systems. Instead, the closest path that does exist is /opt/lsb/lib64. Even then, this path would be wrong because it does not account for the LSBCC_LSBVERSION environment variable which could be set to force a particular LSB version other than the (default) 4.0. I tested setting LSBCC_LSBVERSION and confirmed that Qt's configure script seems to completely ignore it and lots of things break. For now, I just want to get a LSB 4.0 build working and then I can tackle the problems with LSBCC_LSBVERSION (I'll put those in separate bug reports if I get that far).