Hi Christoph, Please remember that mails to n...@bugs.debian.org aren't forwarded to the bug submitter. I saw your message only because I checked the BTS.
fizmo-sdl didn't crash when built from the git repos. I investigated a bit further and discovered that the Debian package crashed because it couldn't load NotoMono-Regular.ttf. And indeed that file didn't exist. I had the fonts-noto package installed but not fonts-noto-mono. Looks like that package needs to be added as a libpixelif-common dependency. Best regards, Peter