Set CXXFLAGS before configure

[dbaston]

Checklist

• [X] Used a fork of the feedstock to propose changes
• [x] Bumped the build number (if the version is unchanged)
• [ ] Reset the build number to 0 (if the version changed)
• [ ] Re-rendered with the latest conda-smithy (Use the phrase code>@<space/conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• [ ] Ensured the license file is being packaged.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[jorisvandenbossche]

@ocefpaf (or someone else of the maintainers) can you take a look at this?

[jorisvandenbossche]

@dbaston this doesn't seem to have solved it. I just created a fresh environment, ensuring it is now using build he1b5a44_1 instead of he1b5a44_0, and I still see the same slowdown in the example of https://github.com/Toblerity/Shapely/issues/847#issuecomment-593598339

[jorisvandenbossche]

Tested with

conda create -n test0 ipython geos=3.8.0=he1b5a44_0 pygeos

and

conda create -n test1 ipython geos=3.8.0=he1b5a44_1 pygeos

and the example code:

import numpy as np
import pygeos

t = np.arange(1, 10000)
arr = pygeos.points(100000*np.sin(t), 100000*np.sin(4*t)) 
arr2 = pygeos.buffer(arr, radius=200, quadsegs=32) 
union = pygeos.union_all(arr2) 

%timeit pygeos.buffer(union, radius=1) 

In both cases this is giving around 3 seconds (while with a local build of GEOS master gives around 60ms)

[jorisvandenbossche]

I checked locally the GEOS 3.8.0 tag as well, and then I also get a slowdown. So it seems the "performance fix" was only commited after 3.8.0, and might be a candidate for backporting to 3.8.x (if not yet done)

[jorisvandenbossche]

The GEOS 3.8.x branch is also slow, so opened https://github.com/libgeos/geos/issues/293

[ocefpaf]

@jorisvandenbossche would patching our 3.8.0 build with https://github.com/libgeos/geos/commit/1bf16cdf5a4827b483a1f712e0597ccb243f58cb help? If so I can do that now and we can add a speed test to the feedstock.

[jorisvandenbossche]

I think the plan is to release a 3.8.1 shortly, so would rather try to get it backported on the GEOS side first

[ocefpaf]

OK. Ping me if you need anything on the conda-forge side.

[jorisvandenbossche]

@ocefpaf it will be fixed in 3.8.1

[ocefpaf]

Awesome! We'll check the ABI and re-pin/migrate as needed.