New to Flatpak, having trouble: VueScan

I’m a long-time Ubuntu/ Mint Linux user but just trying Flatpak for the first time, and have run into frustrating difficulty.

Having used VueScan in Windows, I was excited to see it available for Linux. I followed the instructions on Flathub for installing it. First of all, it seemed incredibly slow to install - nearly an hour. But worst of all, as it seemed to be finishing up, the installation stopped with an error message in a window. Before I could copy the message, poof, it disappeared.

I restarted the install, thinking it might take advantage of what had already been downloaded, but it seemed to be starting over again from scratch. Is this the expected behavior?

I’m using Mint 20.2 on a Dell E7470 laptop.

Install took 2 minutes on a Fedora 34 Workstation install. Generic Desktop machine.

The second time I tried installing VueScan was on another computer, after installing my first app there, Gnome Boxes. This time, the install went fast and completed successfully. I noticed that Gnome Boxes installation installed nine items - taking about an hour over my slow DSL - and VueScan only two. My hypothesis is that the first Flatpak installation involves a number of common libraries that can then be used by subsequent apps without having to reinstall them every time, but I can’t find any documentation that tells me that. I’d be interested to know if that is the case.

if you didn’t have any flatpak app before it had to also download the runtime and that over 1GB.

Thanks, hub. It’s reassuring to know that there is a one-time-only large download that is required. That’s the conclusion I finally came to, and you have confirmed it. But I found nothing about this on flatpak or flathub web sites. In fact, all the documentation I have found thus far is for developers, and almost nothing for users. If there is such, please display it more prominently in the FAQ or some other obvious place.

My impression thus far is that flatpak is a very useful way to maintain and distribute Linux apps. I appreciate the efforts of the developers and this is in no way critical.