I have an annex set up with an s3 special remote. It works fine on one computer. I cloned the annex to a USB stick, plugged the stick into a second computer and cloned the annex to that machine. When I try to git annex initremote cloud on the second machine, I get the following error:

git-annex: Unknown remote type S3

The second machine is running git-annex 3.20121017.