I’d also like to know how to do this. This subtree method seems to end up being about as effective as downloading a copy of trellis and manually merging the changes with meld.
git subtree is much better than
git read-tree indeed!
It avoids errors such as
refusing to merge unrelated histories.
Having the entire trellis + bedrock + sage tree in your repo might be seen as a downside, but it actually helps you keep tract of which updates you have not yet merged into your own project.
Having setup a new project with a slightly modified fork of trellis (some extra bash scripts added, nothing really modified) and following the first few steps with no issues I get this fatal error when running
git diff-tree -r -p HEAD:trellis HEAD:trellis-old full output here:
$ ls README.md site trellis trellis-old $ git diff-tree -r -p HEAD:trellis HEAD:trellis-old fatal: Path 'trellis-old' exists on disk, but not in 'HEAD'.