[PROJ] Switch to proj-datumgrid-geotiff for PROJ 7 ?

[Kristian Evers]

Greg,

> Overall, this makes me think that 7 is being rushed, or that the RFC4
> stuff is being rushed into 7. 

RFC4 is not being rushed. Even and Howard has been working on this
for a long time. The majority of the new code has been ready for more
than a month already. What you are seeing now is the final sprint to
get it polished for release.

> I don't really understand what's driving
> a fixed release date for a major branch, and I don't understand why
> having that fixed date instead of an approach of getting the RFC4 stuff
> done and out for beta and we'll see how it goes.

As you've noticed, PROJ 7 introduces a rather large API break. So did
PROJ 6. Having fixed release dates for this stuff is in my opinion crucial
information for everyone who depends on PROJ. We've announced this
break two years in advance and made a hell of a lot of noise about it so
that it wouldn't come as a surprise for you and everyone else. Overall
I think we have succeeded with that, although not everyone has caught
up yet awareness has been raised and most projects have either already
migrated or have plans to do so soon. I don't think we could have achieved
that with a loosely defined release schedule.

Another benefit of a fixed release schedule is that those of us who
regularly work on PROJ can plan around activities related to releases.
At least for me it is necessary to block a few days in the calendar at release
time. Otherwise the releases would not happen!

Also related to release schedules, recently we had a bit of a mismatch
regarding PROJ, GDAL and QGIS releases that caused some unfortunate
bugs in the 3.4-branch of QGIS. This could probably have been avoided
if we had coordinate releases better between the three projects. That is
something I would like to take into consideration in the future. We need
a discussion between OSGeo projects on the topic. I'll initiate that
sometime soon.

/Kristian