The issue has been filed, link for reference:
https://github.com/ubports/ubports-touch/issues/128

Yeah, this needs definitely some improvement. App development (not only for webapps) is held back by not recieving enough attention for too long making it way to difficult to deliver great applications at the moment. My respect to everyone who is developing anyways, there are some great apps on Ubuntu Touch!

If you have wishes or ideas how to improve the problems, be sure to speak up.

@Emanuele-Sorce, finally I was able to actually reproduce all the required steps to setup build environment once again, so slightly updated guide is now on wiki