Cannot reproduce errors outside of Snap

I am getting a specific error from the upstream application which only occurs in the Snap I’ve created. How can I debug the issue? I am considering rebuilding the upstream application myself so I can add more debugging output.

My Snap is Bisq and the error I am getting is:

$ bisq-desktop 
Picked up JAVA_TOOL_OPTIONS: -Duser.home=/home/david/snap/bisq-desktop/common
error: problem parsing option 'D': D is not a recognized option

The snapcraft.yaml is here: