fix(tests): CIBW test fixes from b-pass→vectorcall branch

- Install multiple-interpreter test modules into wheel (CMakeLists.txt)
  The mod_per_interpreter_gil, mod_shared_interpreter_gil, and
  mod_per_interpreter_gil_with_singleton modules were being built
  but not installed into the wheel when using scikit-build-core.

- Pin numpy 2.4.0 for Python 3.14 CI tests (requirements.txt)
  NumPy 2.4.0 is the first version with official Python 3.14 wheels.

- Add IOS platform constant to tests/env.py

- Skip subinterpreter tests on iOS (test_multiple_interpreters.py)
  Subinterpreters are not supported in the iOS simulator environment.

- Enable pytest timeout of 120s for CIBW tests (pyproject.toml)
  Provides a safety net to catch hanging tests before CI job timeout.

- Disable pytest-timeout for Pyodide (no signal.setitimer)
  Pyodide runs in WebAssembly without POSIX signals.

- Add -v flag for verbose pytest output in CIBW tests

Author: rwgk

tests/CMakeLists.txt

@@ -602,6 +602,12 @@ if(NOT PYBIND11_CUDA_TESTS)
     endif()
   endforeach()
 
+  if(SKBUILD)
+    foreach(mod IN LISTS PYBIND11_MULTIPLE_INTERPRETERS_TEST_MODULES)
+      install(TARGETS "${mod}" LIBRARY DESTINATION .)
+    endforeach()
+  endif()
+
   if(PYBIND11_TEST_SMART_HOLDER)
     foreach(mod IN LISTS PYBIND11_MULTIPLE_INTERPRETERS_TEST_MODULES)
       target_compile_definitions(

tests/env.py

@@ -5,6 +5,7 @@
 import sysconfig
 
 ANDROID = sys.platform.startswith("android")
+IOS = sys.platform.startswith("ios")
 LINUX = sys.platform.startswith("linux")
 MACOS = sys.platform.startswith("darwin")
 WIN = sys.platform.startswith("win32") or sys.platform.startswith("cygwin")

tests/pyproject.toml

@@ -27,7 +27,9 @@ PYBIND11_FINDPYTHON = true
 
 [tool.cibuildwheel]
 test-sources = ["tests", "pyproject.toml"]
-test-command = "python -m pytest -o timeout=0 -p no:cacheprovider tests"
+test-command = "python -m pytest -v -o timeout=120 -p no:cacheprovider tests"
+# Pyodide doesn't have signal.setitimer, so pytest-timeout can't work with timeout > 0
+pyodide.test-command = "python -m pytest -v -o timeout=0 -p no:cacheprovider tests"
 environment.PIP_ONLY_BINARY = "numpy"
 environment.PIP_PREFER_BINARY = "1"
 

tests/requirements.txt

@@ -10,6 +10,7 @@ numpy~=1.22.2; platform_python_implementation=="CPython" and python_version=="3.
 numpy~=1.26.0; platform_python_implementation=="CPython" and python_version>="3.11" and python_version<"3.13" and platform_machine!="ARM64"
 numpy~=2.3.0; platform_python_implementation=="CPython" and python_version>="3.11" and platform_machine=="ARM64"
 numpy~=2.2.0; platform_python_implementation=="CPython" and python_version=="3.13" and platform_machine!="ARM64"
+numpy==2.4.0; platform_python_implementation=="CPython" and python_version>="3.14"
 pytest>=6
 pytest-timeout
 scipy~=1.5.4; platform_python_implementation=="CPython" and python_version<"3.10"

tests/test_multiple_interpreters.py

@@ -9,8 +9,12 @@
 
 import pytest
 
+import env
 import pybind11_tests
 
+if env.IOS:
+    pytest.skip("Subinterpreters not supported on iOS", allow_module_level=True)
+
 # 3.14.0b3+, though sys.implementation.supports_isolated_interpreters is being added in b4
 # Can be simplified when we drop support for the first three betas
 CONCURRENT_INTERPRETERS_SUPPORT = (