.spyx files are treated exactly the same as .pyx files in all of Sage, with one exception: sage --cython foo.spyx adds pre-processing to .spyx files. To be more compatible with other Sage commands (in particular, sage foo.spyx and load("foo.spyx")), we deprecate sage --cython foo.spyx.

There is another reason for this: sage --cython foo.spyx adds some include statements like cdefs.pxi. These .pxi files should be deprecated in Sage. Moreover, .pxi files in general are semi-deprecated anyway by upstream Cython.

CC: @robertwb @jpflori

Component: scripts

Author: Jeroen Demeyer

Branch/Commit: 6984666

Reviewer: Jean-Pierre Flori

Issue created by migration from https://trac.sagemath.org/ticket/22698