Following my Maven build, which successfully produces an APK file at ${WORKSPACE}/target/app.apk, I get the message "Build step 'Upload to Testflight' marked build as failure", with no explanation why it has failed. I have the "Debug upload" option enabled in the advanced section of the plugin config, but there is no other information being displayed in the console from the plugin.

It was working fine last Friday, but as of this week, it has not been uploading any files. The only thing that I recall having changed recently is my Jenkins user's Android debug.keystore file expired and I had to delete it and recreate a new one.

If I perform the upload manually using a command like in the API docs example:

  curl http://testflightapp.com/api/builds.json 
    -F file=@testflightapp.ipa
    -F dsym=@testflightapp.app.dSYM.zip
    -F api_token='your_api_token' 
    -F team_token='your_team_token' 
    -F notes='This build was uploaded via the upload API' 
    -F notify=True 
    -F distribution_lists='Internal, QA'

it uploads correctly, and appears in the TestFlight dashboard. How can I get more information from the plugin about why it is failing to upload my APK?