The Sage Jupyter kernel is unconditionally installed in sys.prefix. However, this should instead be the install_data directory. This defaults to the installation prefix, which in turn defaults to sys.prefix. So the default won't change, but it allows customization.

The reason for choosing install_data is to be compatible with other Jupyter packages, which use the data_files option to setup() for installing Jupyter files (see for example https://github.com/jupyter-widgets/ipywidgets/blob/master/widgetsnbextension/setup.py#L203).
Those files are installed in the install_data directory.

CC: @timokau @kiwifb

Component: distribution

Author: Jeroen Demeyer

Branch/Commit: ad0ee29

Reviewer: Vincent Klein

Issue created by migration from https://trac.sagemath.org/ticket/25546