webapp_usability:_fails_mysteriously_on_newer_repo_layouts.mdwn

### Please describe the problem.

Starting the webapp on a repository that was hastily created by copying an existing one with an older version yields an undecipherable error.

Rather minor.

### What steps will reproduce the problem?

1. Install git-annex from git
2. make a repo
3. copy it over to an external hard drive
4. connect that drive to a wheezy box running git-annex from backports
5. add the external hard drive to the webapp as a new repo
6. boom

I expected git-annex to tell me:

    git-annex: Repository version 5 is not supported. Upgrade git-annex.

Instead, it popped a red box saying a scary "Internal server error". I couldn't read the daemon logs either.

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

original version is:

    git-annex version: 5.20131109-gf2cb5b9

the failing version is running the one from wheezy backports.

### Please provide any additional information below.

screenshot coming up.

> [[fixed|done]] --[[Joey]]