Run 2981 built everything and then died posting the release: HTTP 422, "invalid escape sequence \`". The body's other backticks are written \` because they sit in an UNQUOTED heredoc, where that backslash is the shell's and is gone before any JSON exists. Copying the idiom into a single-quoted variable changed what it meant — single quotes already stop substitution, so the backslash survived into the body as an escape JSON has no rule for. bash -n passes either way; it checks syntax, not what a string becomes. So parse the assembled body for every branch it can take instead, and write down the recipe next to the one for formatting Rust. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MKsUY9Z45KQd34V956hZ9Q