This weekend I tried compiling a project with a library on a Windows machine and got this error:
Cannot install library: directory '/workspace' is a 'simple' format project, please change to a 'extended' format.
The CLI version 2.0.0-libraries.4 doesn’t send the directory structure properly on Windows. It just flattens the hierarchy.
The CLI pre-release 2.0.0-libraries.5 properly preserves the directory structure on Windows.
npm install -g https://github.com/spark/particle-cli/releases/download/v2.0.0-libraries.5/particle-cli-2.0.0-libraries.5.tgz
You may have to delete the previous CLI version to force reinstalling all the dependencies:
del /s /q %USERPROFILE%\AppData\Roaming\npm\node_modules\particle-cli