The .app Bundle contains in the Zip folder attached contains Qt 5.4.1 Framework deployed inside. It means that it contains symlink for example:

Bundle.app/Contents/Frameworks/QtCore.framework/Versions/Current ->
Bundle.app/Contents/Frameworks/QtCore.framework/Versions/5

But also for Resources and Executable.

When repogen is used on this bundle, and then provided in a remote repository, when selecting it in Qt Installer on Windows platform, the installation hang at the first symlink encountered.

It appears that exctrating .7zip folder containing symlink on windows fails.

It could be a bug in 7zip itself or LZMA SDK.

To try this, create a repository (remote?) on Mac OS that contains the bundle attached (after extraction). Define the repository destination on a Windows installer to see it appears during installation and then try to install it.