patch runs ed ————- http://rachelbythebay.com/w/2018/04/05/bangpatch/
Xz format inadequate for long-term archiving
(from the lzip format author) https://www.nongnu.org/lzip/xz_inadequate.html
This of course is sad because we software developers are among the few people who are able to understand the strengths and weaknesses of formats. We have a moral duty to choose wisely the formats we use because everybody else will blindly use whatever formats we choose.