I keep all my php executables in an Ubuntu One folder (for sharing across my computers), and the Ubuntu One folder has a space in it. I found that the self-update command fails due to a problem with curl....for example, in my environment the command become:
$ curl -# -L https://raw.github.com/c9s/Onion/master/onion > /home/matteo/Ubuntu One/dotfiles/bin/onion
so curl complains:
$ curl: (6) Couldn't resolve host 'One'
I found a quick solution that simply escape the spaces in the script path. You can find it here
If you want a PR it's ready...