- remove the old LGPL license headers from all files in Spack
- add SPDX headers to all files
- core and most packages are (Apache-2.0 OR MIT)
- a very small number of remaining packages are LGPL-2.1-only
The build process of Catalyst requires Python at build time (see line 86) even when the +python variant is not selected.
When the +python variant is selected, Python becomes required at build, link, and run time. There doesn't seem to be any restriction on the version of Python required when +python is not selected.
