Thank you Jean, 1. I will try Flatpack 2. Here I was not precise enough: I am already up to date in this repo.
git pull says that I am "Already up to date." I apparently forked it back then. The upstream is https://github.com/openlilylib/snippets.git And the latest commit is from 2019 https://github.com/openlilylib/snippets/commits/master
Is that the best and most recent source for OpenLilyLib? In particular, is this the latest edition engraver? https://github.com/openlilylib/snippets/tree/master/editorial-tools/edition-engraver Thanks, Michael