I'm not sure how this happened (maybe I typed a command line vi ~ /extra/space.txt?) but there is now a file named ~ staged for commit. I do not want to add it to git, and I'm hesitant to try rm ~ before thinking through possible side effects.
$ git status
On branch master
All conflicts fixed but you are still merging.
(use "git commit" to conclude merge)
Changes to be committed:
modified: apples.js
modified: app/berries.js
modified: app/views/pears.js
new file: app/views/lemons.js
modified: public/stylesheets/oranges.css
new file: ~