Projects in the topic rpm
RPM Package Manager is a free and open-source package management system.

Has anybody ever heard about RPM Spec LSP server? That would be awesome thing to have (at least for completion)? The best I know is this: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/KBJYLQZ6VNSCWBNC7Y72HTBJ6EQDVFMX/