These are notes that are shared as a technique that can be applied to other third-party projects to add CMake to them without disturbing project source code.
A major point release is like 5.5.0 to 5.6.0. For MUMPS, there are typically changes in the source files used, so the Makefiles must be inspected for changes.
When a new MUMPS major release occurs, download both the prior release and the current release. Extract both release archives into distinct directories.
Do a "diff" of the Makefiles--perhaps via Meld. This will show if there are any new and/or removed source files. Update the CMake scripts according to any relevant Makefile changes.
A minor point release is like 5.6.0 to 5.6.1. For MUMPS, there are typically not changes in the source files used, though it's always a good practice to check the Makefiles.
Example: minor release patch.
The URL of the new release can be extrapolated from libraries.json.
Change the default MUMPS_UPSTREAM_VERSION to the latest release.
Upload the latest MUMPS source archive to Zenodo using "new version". Zenodo is faster and more reliable than MUMPS server hosting. Update cmake/libraries.json to point to the new source archive URLs.