<hr /><i>anonymous claiming to be mgagnon added on 2011-06-01 11:28:34 UTC:</i><br />
Personally, opening a sqlite3 database on my home directory is not destructive. And for most of the command, it doesn't write to it. Most program access home directory to store settings, and for that, ou don't have to explicitly ask for it. 

However, it's may be a bit excessive to fail if this ~/.fossil file cannot be found or open for a command like "fossil timeline" which would be able to do the work without it.