Changed in version 3.27: When UPDATE_DISCONNECTED is true, the update step will be executed if any details about the update or download step are changed. Furthermore, if using the git download/update method, the update logic will be modified to skip attempts to contact the remote. If the GIT_TAG mentions a ref that is not known locally, the update step will halt with a fatal error.
Cmake was pinned to <3.27 to avoid problems with updating MSlice as an external project.
The setting for UPDATE_DISCONNECTED gets ignored otherwise.
From cmake docs here:
Changed in version 3.27: When UPDATE_DISCONNECTED is true, the update step will be executed if any details about the update or download step are changed. Furthermore, if using the git download/update method, the update logic will be modified to skip attempts to contact the remote. If the GIT_TAG mentions a ref that is not known locally, the update step will halt with a fatal error.