Today I upgraded to xubuntu 18.04 sphynx could not start, even if parrot repo is reset to available, I could not install nor start https://pastebin.com/JJgBDkSx
Have you tried installing libcurl3 manually before sphinx?
sudo apt-get remove --purge parrot-sphinx sudo apt-get install libcurl3 sudo apt-get install parrot-sphinx
You may also want to check that
/etc/apt/sources.list.d/sphinx.list contains the following line before installing sphinx:
deb http://plf.parrot.com/sphinx/binary bionic/
Obviously i did then i got the message that libcurl3 conflicted with libcurl4. So After an apt purge and an installation of a other package, the problem disappered reinstalling sphynx. There could be no drone in simulator, world was build, no drone ready. But I tried Just once.
Could you help also in recompile a new firmware for swing?