Apache Toree is looking for the spark home directory (defaults to "/usr/local/spark", but when it can't find the directory due to spark having been installed via Homebrew, it throws an exception.
jupyter toree install
FileNotFoundError: [Errno 2] No such file or directory: '/usr/local/spark/python/lib'
Where is the spark home when spark is installed via homebrew?
The directory Apache Toree is looking for when spark is installed via homebrew is in /usr/local/Cellar:
jupyter toree install --spark_home /usr/local/Cellar/apache-spark/2.1.0/libexec
/usr/local/Cellar/apache-spark/2.1.0/libexec/
It specifically wants the "libexec" directory where it can go into the "python/lib" sub-directory.