Sorry for the delay @mbeneto, I’m sorry to say that I somehow missed your response.
No, I was suggesting you test the snap as given in the PR description (using the snap), which you did. However, I didn’t realize that the channel had already been closed, which means you magically got edge instead, which is of course still broken (it seems rather unfriendly that you can still install from closed channels 
). Indeed, I suspect snapcraft-pr won’t work on Trusty, either.
This work stalled for a bit since we decided to solve building on Trusty via build VMs instead of the route given in the PR. We expect the ETA for that to land is still several weeks, I’m afraid.
I’m curious: can you explain why you’ve settled on classic confinement as opposed to strict? That works better on Trusty, and is something you can do today.