So, to follow up on this I've gotten ECL running on the SailfishOS emulator. In the end (after finding the right web page) it was pretty easy to get shell access to the emulator and run `./configure`, `make` and `make install` there. Although it's a cross-compilation environment it worked without an issue.
Now on the EQL! (SailfishOS runs QT (but with their own layer on top of it :-( ).)
And then try to get it running on the actual phone...
Thanks again, Erik