I added repo.merproject.org to allowed sites in my ISP control panel and now I can access it.

Downloaded and installed 1.16.0+master etc. Started Pure Maps. The rendering seems fine but I cannot test any more since a) Pure Maps does not know where I am (probably because the GPS location got lost when I wiped the phone after a bodged update to Rokua) and b) I cannot go out anyway to play with it due to the lockdown.

EDIT:
The phone found itself after I put it in the window. Located a random route. In its usual style, it underestimated the travel time (Google and Bing say 45 minutes, Pure Maps says 39), but the route is as expected.

Anything else I can try?