### Please describe the problem.

Setting git-annex on an Android device (either the released version, or the autobuilder apk), I'm told:

[[!format sh """
git-annex: unknown command webapp
"""]]

Looking in the logs on the Android autobuilder I see many instances of:

[[!format sh """
#warning Building without the webapp. You probably need to install Yesod..
"""]]

### What steps will reproduce the problem?

Run git-annex.

### What version of git-annex are you using? On what operating system?

v5.20150617~g031b85a

### Please provide any additional information below.

[[!format sh """
# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/annex/daemon.log


# End of transcript or log.
"""]]