Rapid Photo Downloader 0.9.0a4 is released

As far as I understand you are trying to install an (incomplete) alpha version. I would guess once it’s ready for release you will get packages that are easy to install for major distributions and a while after that the distributions will package the new version and you will install it even simpler. As you installed the “old” version (0.4.11 is the latest released version).

The complicated install procedure you are describing is for early testers.