I had good luck getting Obsidian running on my Pi 5 via Flathub, especially once I turned on Wayland support. But so far I'm stuck getting Obsidian running under Asahi Fedora Remix 42, the spring release of Fedora running on top of MacBook Air M1 hardware.
I'm at the stage where I don't even have a good bug report yet, but I'll get there next and update this with it. It seems to have something to do with video drivers.
Update 2025-04-23:
The underlying problem is that the version of Electron being used has a page size bug, which causes systems with 16K pages (incluing the Pi 5 and Asahi Linux on the Apple M1) to crash when running this application in version 1.8.9.
I didn't notice this on my Pi 5 because I'm still on an older version.
The version affected is Obsidian 1.8.9. Earlier versions from 1.8.7 back are not affected, and the newest 1.8.10 has a specific fix for this on arm64 released in the app image and .tar.gz formats.
I have not tested the newest Flathub release yet.
The #linux channel of the Obsidian Members Group (OMG) on Discord has had helpful people, thanks to WhiteNoise and to jstone.
