POV-Ray v3.7.1 has been redesignated v3.8.0, and we'll be back at alpha
stage for now.
As with previous alphas, this is a binary-only release without
installer; the binaries want to ride piggyback on an existing v3.7.0
installation.
https://github.com/POV-Ray/povray/releases/tag/v3.8.0-alpha.9309453
