NPM installation issues with MacOS 10.15.2 beta 1
Update:

Remove most of this:

The root cause of the issue is the updating of the fsevents binaries by the author.  Once they do that, the issue should be resolved.

The fsevents team has provided recommendations to resolve in the meantime via their github issues page.

https://github.com/fsevents/fsevents/issues/291


I went back to the drawing board.  It turns out that when I looked at the github issue closer, someone actually nailed the root cause with this handy little tidbit.


  This is not something to be "fixed". One needs to have XCode
  command-line tools installed in order to install/compile native
  modules.
  
  There no longer are credentials for AWS. So the installs are actually
  a bit risky. In addition 1.2.x is really deprecated. I've just done a
  release that removes node-pre-gyp dependency and therefore the
  ability/failure to download prebuilt binaries.


I had just re-installed Xcode but had neglected to add the CLT.  Done... Fixed the problem.