I haven't been able to install flatpaks on a clean installation of Fedora 30 for a month now. This bug has the most complete and recent information: https://bugzilla.redhat.com/show_bug.cgi?id=1697566
The biggest issue is no one really knows exactly what the problem is so there's a lot of finger pointing, most of it centered on libcurl version. Supposedly the fix was backported to 7.64.0-8.fc30 but that hasn't actually fixed the problem; today a user reports that upstream master/7.65.2 did fix the problem. But what's the policy for rebasing to that? Is the Fedora libcurl maintainer expected to figure out what fixes it and backport it? The verbose output is not that helpful, and libcurl folks are like, this is too complicated with too many layers, try to reproduce it with libcurl directly - and I'm like, that's pretty unlikely.
Perhaps more likely is maybe asking this user to bisect and find out the good commit that fixes the problem, and ask the Fedora libcurl maintainer to backport that?
Anyway, if it's better for me to file a WG issue and we can discuss it at Monday's meeting, I'll do that.