There are wrong blank lines in the diff view. For https://app.graphite.dev/github/pr/spockframework/spock/1692 the PR details view in the dashboard shows line 1045 as unchanged, and line 1066 as added. GitHub show line 1045 as added and no line 1066.

gitk

also shows it like GitHub.

git diff

also shows it like GitHub. I assume when retrieving the text to diff, you somehow get an extra blank line in the end which then manifests like that. The files have a final newline character like any good text file should have. 🙂