The error message refers to larch.db, which wasn't added until Larch
1.1.0 (currently in development). Did you perhaps install the Larch
development gem at some point? It seems like you've got an odd mix of
Larch components -- possibly a 1.1.0 binary and a 1.0.2 lib.
Try completely uninstalling Larch (all versions) with `gem uninstall
larch`, then reinstall whichever version you prefer to use.
- Ryan