"make sis QT_SIS_TARGET=release-armv5" doesn't work for binary packages

Install the package, then try to redo creating the qt_libs....sis files. For example for a self-signed version, do to the following:

cd src\s60installs
qmake
patch_capabilities.pl Qt_for_S60_template.pkg release-armv5
make sis QT_SIS_TARGET=release-armv5

this results into:

C:\Qt\4.6.0-20090929\src\s60installs>make sis QT_SIS_TARGET=release-armv5
2: make -s -f Makefile fail_sis_nocache
3: Makefile:122: *** Project has to be build before calling 'SIS' target. Stop.

If you create a .make.cache file inside of src\s60installs it will work though.