This skill runs only on macOS and Linux, and insists on starting from the main branch so the new feature branch is based on the right commit; it validates that the version argument matches the X.Y.Z format before touching anything.
It checks that aws and wget are installed and that AWS credentials actually work, stopping immediately if either check fails rather than discovering the problem after files are already edited. Once checks pass, it creates a version-named branch and updates the COPILOT_VERSION string in NEWS.md and in the dependency install and upload scripts, each of which uses a slightly different syntax that must be matched exactly.