Toolchain issues: npm 7 causes problems

As of Joplin 2.3 the project uses npm 7. The following post only applies to Joplin < 2.3.

In case somebody else experiences problems with building Joplin or running scripts defined in package.json.

npm 7.x causes the toolchain to fail. The current fix is to downgrade to the latest 6.x version of npm.

Here are issues that have been recorded so far: