svn: E175002: Received fatal alert: protocol_version
Jenkins could not check out from Subversion behind Cloudflare. The alert is a TLS version mismatch between SVNKit and a repository set to TLS 1.3.
subversion
A release process built on trunk, tags and branches
Who owns trunk, what a tag is for, and where a developer's branch fits — the repository layout behind a release, drawn as one diagram.