Cannot build C-extension in Python 3.6

[pllim]

c/c @cdsontag

As reported by @olebole below:

When compiling for Python 3 (3.6), ... the C modules (sscanf and xutil) don't work "out of the box".
Pragmatically, I could resolve that by renaming them in setup.cfg:

-[extension=pyraf.sscanfmodule]
+[extension=pyraf.sscanf]
 sources = src/sscanfmodule.c
 optional = True
 fail_message = If this is Windows, it is ok.

-[extension=pyraf.xutilmodule]
+[extension=pyraf.xutil]
 ...

but I am not sure whether this is the best solution. Any idea?

[cdsontag]

I sorta handled that in pyraf/defsetup.py with the C_EXT_MODNAME_ENDING var, but if you aren't using that file during install, then yes, that's the basic change.

The two C source code files in pyraf/src should not need any changes bc they already include if-blocks for that name change and IIRC for other Py2-v-Py3 changes.

[olebole]

I used the 2.1.14 release which does not contain defsetup.py.
It gets a bit confusing now, since there are three potential setup scripts:

• setup.py
• defsetup.py
• lib/pyraf_setup.py

The default build under Debian uses setup.py, with the described problem. However, it seems that the patch shown above also works well for Python 2.7; so it may be worth to just apply this one?

Generally, what is the preferred way to build + install the package?

[pllim]

I think #1 might already address this -- @jhunkeler ?

[pllim]

Update: I applied your suggested patch in #54, @olebole . FYI.