In December 2017, the author posted an update saying that he is rewriting the project and version 1 will no longer be supported.
Miniflux 2 is a rewrite of Miniflux 1.x in Golang. The development still in progress and it's not ready to be used.https://miniflux.net/news
The code base of Miniflux 1.x is getting old. It was time to move to something else.Miniflux 1.x is now considered legacy and the efforts will go on Miniflux 2.
As part of the deprecation of Miniflux 1, the feed parsing library picoFeed is no longer supported.