`npm cache add ` does not work

Question

I pack an NPM library with:

tarball=$(npm pack)

then I run

npm cache add "$PWD/$tarball"

but when I inspect the npm cache in .npm, there's nothing new there.

Does anyone know why the NPM cache would not get updated by the add command?

Answer 1

I came across the very same problem on Windows2012 machine when using npm version 5.3.0. Moving on to 5.6.0 it is no longer a problem.