TMI: Miscellaneous cleanup

Spent most of today trying to figure out why tests failed on my RUST_PATH pull request. I eventually narrowed it down: I was using "" as the default when the RUST_PATH environment variable wasn't set, and using an iterator to parse the result (which is a colon-separated list of strings). When given the empty string, the iterator returns [""] rather than (as I'd expect) []. I wonder if that's actually a bug in the library. In any case, it was easy to work around once I saw what the problem was.

Also figured out why the non-rustpkg test cases I was trying to add yesterday were failing, or at least: the bug from yesterday went away when I rebased, but a new bug happened. That one turned out to be due to recent changes to terminfo that affect how warnings get rendered. The totally-obvious fix was to set my TERM to xterm (oh, emacs shell, why must you always be problematic).

It doesn't feel like a very productive day, but hey, I have four pull requests in the queue. Tomorrow, working on the package database, I guess?!