PROJ_CURL_CA_BUNDLE global env var not being picked up

[brynpickering]

I only have experience with using PROJ via pyproj, but the issue I raised there (pyproj4/pyproj#1233) seems more appropriate here. Namely, PROJ seems to not be picking up my globally set environment variables when it receives an empty string to proj_context_set_ca_bundle_path.

Example of problem

using pyproj:

from pyproj.network import set_ca_bundle_path, set_network_enabled
from pyproj.transformer import Transformer

set_network_enabled(True)
set_ca_bundle_path()
t = Transformer.from_crs("epsg:27700", "epsg:4326")
print(t.transform(0, 0, None, errcheck=True))

I get the error: transform error: Network error when accessing a remote resource: (Internal Proj Error: Cannot open https://cdn.proj.org/uk_os_OSTN15_NTv2_OSGBtoETRS.tif: SSL certificate problem: unable to get local issuer certificate)

Even though I have both PROJ_CURL_CA_BUNDLE and CURL_CA_BUNDLE set globally on my machine.

Passing the path to my CA bundle explicitly to set_ca_bundle_path (and therefore proj_context_set_ca_bundle_path) works as expected.

Problem description

I have a limited understanding of C, but since it is strongly typed I assume proj_context_set_ca_bundle_path has to receive a string when called. pyproj goes with an empty string to invoke a search through the available environment variables in PROJ and I would expect this to land on the path to my CA bundle.

Environment Information

• PROJ version (proj): 9.3.0
• Operation System Information: osx-arm64 (Sonoma v14.1.2)

Installation method

• conda (conda-forge channel)

[rouault]

PROJ seems to not be picking up my globally set environment variables when it receives an empty string to proj_context_set_ca_bundle_path.

yes this is intended. If the user calls proj_context_set_ca_bundle_path(), this overrides whatever was set through the environment variables. Probably the fix should be on pyproj4 side to not call proj_context_set_ca_bundle_path() if they are set.

[brynpickering]

OK, I just tried removing the call to proj_context_set_ca_bundle_path in pyproj initialisation and the SSL certificate problem persists. Does this suggest that PROJ isn't finding the environment variables of its own accord?