Mk/Uses/python.mk Add python-config helper variables

[koobs]

Summary

Proposed commit log:

Mk/Uses/python.mk Add python-config helper variables

Add convenience variables to python.mk for python[x.y]-config values to 
make it easier for ports that depend on Python to introspect the
installed Python configuration or build settings.

Update textproc/py*-libxml2 and editors/libreoffice ports to use the new
variables.

While I'm here:

- Rename PYTHON_ABIVER (canonically) to PYTHON_ABIFLAGS
- Move MAINTAINER details to the file header
- Make PYTHON*_DEFAULT_VERSION deprecation warning stronger
- Clarify PYTHON_DEFAULT vs installed default version messaging

Maintainers of py*-libxml2 and libreoffice are added as reviewers, and last
committer to py*-libxml2

[mva]

Mk/Uses/python.mk

3

All(?) Uses files keep MAINTAINER at the end of the header comment. Please keep this consistent.

159

Was the whole tree checked for the usage of PYTHON_ABIVER?

393

All of those should be properly documented in the header section.

[antoine]

PYTHON_CFLAGS, PYTHON_LIBS ... conflict with CFLAGS, LIBS... option helpers for the PYTHON option

Using != for commands in LOCALBASE is usually not a good idea:
Running make from the modified ports used to work when python was not yet installed , and or no longer works

[koobs]

Mk/Uses/python.mk

3

It would be nice if these were (all?) moved to the top. It's good to have the contact point more visible, especially for long .mk files like ours and others. cc portmgr

I'll change it to maintain consistency

159

Yes:

find /usr/ports -exec grep -i PYTHON_ABIVER {} +

/usr/ports/Mk/Uses/python.mk:# PYTHON_ABIVER            - Additional ABI flags set by the chosen Python
/usr/ports/Mk/Uses/python.mk:PYTHON_ABIVER=             # empty
/usr/ports/Mk/Uses/python.mk:PYTHON_ABIVER!=            ${PYTHON_CMD}-config --abiflags
/usr/ports/Mk/Uses/python.mk:PYTHON_INCLUDEDIR= ${PYTHONBASE}/include/python${_PYTHON_VERSION}${PYTHON_ABIVER}

393

Ah yes, I knew. I forgot something

[koobs]

In D3010#59310, @antoine wrote:

PYTHON_CFLAGS, PYTHON_LIBS ... conflict with CFLAGS, LIBS... option helpers for the PYTHON option

Using != for commands in LOCALBASE is usually not a good idea:
Running make from the modified ports used to work when python was not yet installed , and or no longer works

I originally had these in PYTHON_CONFIG_*, are these ok?

[antoine]

In D3010#59321, @koobs wrote:

In D3010#59310, @antoine wrote:

PYTHON_CFLAGS, PYTHON_LIBS ... conflict with CFLAGS, LIBS... option helpers for the PYTHON option

Using != for commands in LOCALBASE is usually not a good idea:
Running make from the modified ports used to work when python was not yet installed , and or no longer works

I originally had these in PYTHON_CONFIG_*, are these ok?

This is still a bit ambiguous for port developers.

Also this doesn't solve the problem of != with command in LOCALBASE

[koobs]

I've been made aware (thanks @antoine) that this is likely impossible to achieve given there are cases where Python (and thus PYTHON_CONFIG_CMD) will not (yet) be installed.

Abandoning unless anyone has ideas.