It looks like python-magic isn’t able to build right now due to a missing dependency of libmagic. Normally you could add the missing dependency through the configuration tab but doing so unfortunately will break your Linux build. I’ve filed a bug with the build team to get this issue resolved in the Platform. We’ll report back here when the issue is resolved.
Unfortunately not. Looks like the latest version of Fava and Beancount don’t have the proper dependencies for anything. Which is why the build stop failing on python-magic.