You’re jumping the gun a bit…
At the Inkscape website, 0.92.4 is the “current stable” while 1.0 is available as “the next” version
It also looks like 1.0 is currently available to Linux as an AppImage which is similar to snap… distributed as a pre-built app packaged with its dependencies and OS stub so that it’ll run on any HostOS distro.
You can pick/choose what version you want for Snap – stable, beta or ‘next’. And, apparently as you mention, for AppImage.
The only issue I’m asking about is re: builds of Inkscape in the openSUSE obs. Doesn’t matter what version really – the fact that they’re failing, and there’s no bug-owner to report to is the problem/question …
Builds are successful for Factory, Tumbleweed, and 15.2.
Although builds are failing for 15.1 and 15.2, 'Current, stable" packages are available for 15.1 and 15.0.
So,
Although you can report it to the openSUSE bugzilla, I doubt that there is any need for action… At least, for now there is no problem for anyone who wants to install Inkscape form an openSUSE repository.
From the compiler error and the fact that it builds with gcc9 and fails with gcc8 it looks like gcc bug. You may consider opening bug report against Leap 15.1 gcc pointing to the error in build logs. Of course inkscape upstream bug report about this problem with gcc8 also makes sense. If they suggest patch, you can always submit request for inkscape pointing to upstream.