Can't PUT new confighash via callback_url

[friism]

I'm experimenting with updating the config hash of a provisioned add-
on. I can successfully GET the callback_url using this command:

curl https://appharbordonothingaddon:p...@api.heroku.com/vendor/apps/788791

I cannot PUT a new config hash, however:

curl -H "Accept: application/json" -X PUT -d @data
https://appharboonothingaddon:p...@api.heroku.com/vendor/apps/788791 -w
"%{http_code}"

The data file (@data) contains stuff along these lines:
{"APPHARBORDONOTHINGADDON_CONFIGVAR":"Bar"}

(I've also experimented with {"config":{...}} etc.).

Heroku always return http 500. What am I doing wrong?

Michael

[friism]

This turned out to an error on my part, the correct JSON to PUT looks
like this:
'{"config": {"APPHARBORDONOTHINGADDON_CONFIGVAR":"Baz"}}'

Michael