merge c_stdlib_version & MACOSX_DEPLOYMENT_TARGET on osx

conda_smithy/configure_feedstock.py

@@ -520,6 +520,39 @@ def _collapse_subpackage_variants(
         "BUILD",
     }
 
+    # on osx, merge MACOSX_DEPLOYMENT_TARGET & c_stdlib_version to max of either; see #1884
+    if squished_used_variants["target_platform"][0].startswith("osx"):
+        # in global pinning, but use fallback to avoid having to set it in all tests
+        v_stdlib = squished_used_variants.get("c_stdlib_version", ["0.0"])
+        # also in global pinning, but prepare for eventualy disappearance
+        macdt = squished_used_variants.get("MACOSX_DEPLOYMENT_TARGET", [None])
+        # the merge logic only deals with one version
+        if (len(v_stdlib) > 1 and macdt[0] is not None) or len(macdt) > 1:
+            raise ValueError(
+                "Not prepared to deal with multiple c_stdlib_version that do not match "
+                "MACOSX_DEPLOYMENT_TARGET! Please delete MACOSX_DEPLOYMENT_TARGET and "
+                "use only c_stdlib_version on osx."
+            )
+        # now that we ruled out multiple values, extract it from list
+        v_stdlib = v_stdlib[0]
+        macdt = macdt[0]
+        if macdt is not None and v_stdlib != macdt:
+            logger.warn(
+                "Duplicate specification of macosx deployment target!\n"
+                "If your conda_build_config.yaml sets `MACOSX_DEPLOYMENT_TARGET`, "
+                "please change the name of that key to `c_stdlib_version`!"
+            )
+            cond = VersionOrder(v_stdlib) > VersionOrder(macdt)
+            new_val = v_stdlib if cond else macdt
+            squished_used_variants["c_stdlib_version"] = [new_val]
+
+        # in any case, we set MACOSX_DEPLOYMENT_TARGET to match c_stdlib_version
+        # (if it is set), for ease of use in conda-forge-ci-setup
+        if "c_stdlib_version" in squished_used_variants:
+            squished_used_variants["MACOSX_DEPLOYMENT_TARGET"] = (
+                squished_used_variants["c_stdlib_version"]
+            )
+
     if not is_noarch:
         always_keep_keys.add("target_platform")
 

news/1889-merge-c_stdlib_version-and-MACOSX_DEPLOYMENT_TARGET-on-osx.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* Ensure we populate MACOSX_DEPLOYMENT_TARGET for use in conda-forge-ci-setup also when using `c_stdlib_version` (#1884 via #1889)
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* <news item>
+
+**Security:**
+
+* <news item>

tests/conftest.py

@@ -241,6 +241,30 @@ def stdlib_recipe(config_yaml, request):
     )
 
 
+@pytest.fixture(scope="function")
+def stdlib_deployment_target_recipe(config_yaml, stdlib_recipe):
+    # append to existing stdlib_config.yaml from stdlib_recipe
+    with open(
+        os.path.join(config_yaml, "recipe", "stdlib_config.yaml"), "a"
+    ) as f:
+        f.write(
+            """\
+MACOSX_DEPLOYMENT_TARGET:       # [osx]
+  - 10.14                       # [osx and x86_64]
+  - 12.0                        # [osx and arm64]
+"""
+        )
+    return RecipeConfigPair(
+        str(config_yaml),
+        _load_forge_config(
+            config_yaml,
+            exclusive_config_file=os.path.join(
+                config_yaml, "recipe", "stdlib_config.yaml"
+            ),
+        ),
+    )
+
+
 @pytest.fixture(scope="function")
 def upload_on_branch_recipe(config_yaml, request):
     with open(os.path.join(config_yaml, "recipe", "meta.yaml"), "w") as fh:

tests/test_configure_feedstock.py

@@ -246,6 +246,32 @@ def test_stdlib_on_azure(stdlib_recipe, jinja_env):
     # no stdlib-version expected on windows
 
 
+def test_stdlib_deployment_target(
+    stdlib_deployment_target_recipe, jinja_env, caplog
+):
+    with caplog.at_level(logging.WARNING):
+        configure_feedstock.render_azure(
+            jinja_env=jinja_env,
+            forge_config=stdlib_deployment_target_recipe.config,
+            forge_dir=stdlib_deployment_target_recipe.recipe,
+        )
+    # this configuration should be run
+    assert stdlib_deployment_target_recipe.config["azure"]["enabled"]
+    matrix_dir = os.path.join(
+        stdlib_deployment_target_recipe.recipe, ".ci_support"
+    )
+    assert os.path.isdir(matrix_dir)
+    with open(os.path.join(matrix_dir, "osx_64_.yaml")) as f:
+        lines = f.readlines()
+        content = "".join(lines)
+    # ensure both MACOSX_DEPLOYMENT_TARGET and c_stdlib_version match
+    # the maximum of either, c.f. stdlib_deployment_target_recipe fixture
+    assert bool(re.match(r"(?s).*c_stdlib_version:\s*- ['\"]?10\.14", content))
+    assert bool(
+        re.match(r"(?s).*MACOSX_DEPLOYMENT_TARGET:\s*- ['\"]?10\.14", content)
+    )
+
+
 def test_upload_on_branch_azure(upload_on_branch_recipe, jinja_env):
     configure_feedstock.render_azure(
         jinja_env=jinja_env,