Running npm install on a main project with subproject npm linked inside, seems to break the node_modules of the subproject until I run npm install again in the subproject.

# npm --version
6.14.13

Googling shows many people running into this for years, so I’ve migrated to Yarn 1.

yarn add and yarn remove don’t have this problem.

Not Yarn2, because ionic seems to trip over it:

ionic build
> react-scripts build
'react-scripts' is not recognized as an internal or external command,
operable program or batch file.

[INFO] Looks like react-scripts isn't installed in this project.

       This package is required for this command to work properly.

? Install react-scripts? Yes
> yarn.cmd add --dev --exact --non-interactive react-scripts
Unknown Syntax Error: Unsupported option name ("--non-interactive").

$ yarn add [--json] [-E,--exact] [-T,--tilde] [-C,--caret] [-D,--dev] [-P,--peer] [-O,--optional] [--prefer-dev] [-i,--interactive] [--cached] ...
[ERROR] An error occurred while running subprocess yarn.

        yarn.cmd add --dev --exact --non-interactive react-scripts exited with exit code 1.

        Re-running this command with the --verbose flag may provide more information.