Segmentation fault when using both eccodes and pygrib in the same Python script

[zhenkunl]

Description:
I am experiencing a segmentation fault or ECCODES runtime errors when using both eccodes (Python bindings) and pygrib in the same script. The crash/error occurs depending on the order of operations.

Steps to reproduce:

Scenario 1 (segmentation fault):

from eccodes import *
import pygrib

f = open("1.grib", 'rb')
gid = codes_grib_new_from_file(f)
codes_release(gid)
f.close()

grbs = pygrib.open("2.grib")   # Segmentation fault here

Scenario 2 (ECCODES runtime error):

from eccodes import *
import pygrib

grbs = pygrib.open("2.grib")   # This succeeds
f = open("1.grib", 'rb')
gid = codes_grib_new_from_file(f)   # Error occurs here

Error output for Scenario 2:

ECCODES ERROR   :  STL exception: unordered_map::at
ECCODES ERROR   :  Runtime error
ECCODES ERROR   :  grib_handle_new_from_file_no_multi: Cannot create handle

Expected behavior:
Both libraries should be usable in the same script without conflicts, regardless of the order of file operations.

Actual behavior:

• If eccodes is used first, a segmentation fault occurs when later calling pygrib.open().

• If pygrib is used first, eccodes operations fail with an ECCODES internal error (unordered_map::at).

Environment:

• eccodes Python bindings version: 2.47.0

• eccodeslib version: 2.46.2.19

• pygrib version: 2.1.8

• Operating system: Ubuntu 24.04

• Python version: 3.12/3.13

Additional context:
Both packages are wrappers around the ECCODES C library. The errors suggest that the two bindings are not isolated – they interfere with each other's internal state (e.g., global contexts, error queues, or C++ static objects). This makes it impossible to use both packages together in the same Python process.

Possible workaround:
Use only one of the libraries in a given Python session. Alternatively, one might try to load them in separate subprocesses, but that is not a real solution for interactive workflows.

Please investigate whether the Python bindings for ECCODES can be made safe for co-existence with pygrib. Thank you!

[jswhit]

This is a generic problem with python C extensions that modify the global state of the C libs. I don't know how I can solve this on the python side.