This was written before local-exported variables did anything useful.
Passing these vars as local-exports removes the need to define the
validation function with `--no-scope-shadowing` which is quite the
hack.
This is apparently quite slow on large svn repos (like 40 seconds
slow), and we don't have a good thing to display other than the full
file information.
So we'll have to disable it for now.
Fixes#6681.
[ci skip]
