Where is Rsync's default temp directory? I'm using rsync to backup files to an external hard drive; my boot disk is pretty full. Rsync keeps failing due to not enough disk space to build the temporary file list, and unfortunately doesn't delete the temp files. My question: where are those temporary files kept? I'd like to go and delete them manually.
Ok, figured it out.

I was running a simple rsync command: rsync -av /Users/kenneth /foo
where /foo is the former location of an external drive. Instead of directing rsync to the current location, I was creating a new location and writing to it, simply duplicating files on my boot drive.

Lesson: read your command twice and double-check before running it.