No problem. Glad to hear you got it going.
I was a little sad to see that the Debian Stable repo is still at Sigil 0.9.13, though.

They've got Qt5.11.x and Python 3.7.x, so there's nothing really holding them back. I suppose it's the whole QtWebEngine debate holding them up. But at least it's pretty easy to get a much newer version from the Stable Backports repository!