# cython: cdivision=True

[was]

The file matrix_window_modn_dense.pyx starts with

# cython: cdivision=True

which suggests that putting a line like

# cython: cdivision=False

would have an impact on the directives used when compiling Cython code. This is not the case at all. Such a line is completely ignored.

To resolve this ticket, either make the directive not be ignored, or delete this line from matrix_window_modn_dense.pyx.

Note that the actual directories used are currently hard coded in devel/sage/sage/setup.py in this code:

        # call cython, abort if it failed
        cmd = "python `which cython` %s --old-style-globals --disable-function-redefinition --embed-positions --directive cdivision=True,autotestdict=False,fast_getattr=True -I%s -o %s %s"%(cplus, os.getcwd(), outfile, f)
        r = run_command(cmd)

The default with PSAGE is cdivision=False. This is causing me headaches when porting code from psage to sage. (E.g., #12465). For #12465 I'll probably try to figure out how to rewrite my code to work with cdivision=True, or use explicit cython directives on a function-by-function level.

[was]

OK, now I feel stupid. So even though the command line explicitly has --directive cdivision=True,, when cython sees the file it does cdivision=False, as long as # cython: cdivision=False is in the file. So I'm basically just totally wrong. I'm closing this ticket as invalid. Sorry for the noise and confusion.