Hi,
I’m planning to do a 18.1.1 release tomorrow to fix the issue with the rc version suffix. 18.1.2 will be moved up to March 19, and then the point releases will continue every two weeks after that.
I apologize for this mistake, I completely missed this when cutting the release. If this is causing a major problem for you currently, you can work around this by passing -DLLVM_VERSION_SUFFIX=""
to cmake when you configure the project.