Just found another bug in WarpIn 1.0.19. References to the value of the TARGET attribute in another PCK tag in the form of "$(N)" (where N is the number of the referred package) are not updated if you change the original value they refer to. In case of Qt4 WPIs this means that if one attempts to change the path of the "Installation Utilities" package in qt-lib-4_6_2.wpi to something else instead of the default value, paths to all other packages referring to it (plugins, translations, etc) will NOT be updated (and there is no way to change then as they are FIXED by design). As a result, the user will get a seriously broken Qt 4 installation (in particular, no plugins can be found and all the fancy stuff it leads to).
Unfortunately I cannot report a WarpIn bug at xtracker.netlabs.org since I forgot my password and there is no visible interface to recall it.
Anyway, as I doubt that the problem will be fixed soon even if I report it, we will have to find some acceptable workaround in the Qt 4.6.3 release.