conda · travishathaway · Jun 23, 2025 · Jun 23, 2025 · Jun 23, 2025 · Jun 23, 2025
@@ -12,8 +12,10 @@
     _StoreAction,
     _SubParsersAction,
 )
+from pathlib import Path
 
 from .. import CondaError
+from ..cli.main_config import set_keys
 from ..deprecations import deprecated
 from ..notices import notices
 
@@ -209,6 +211,12 @@ def execute(args: Namespace, parser: ArgumentParser) -> int:
                         )
                     )
 
+        if context.subdir != context._native_subdir():
+            set_keys(
+                ("subdir", context.subdir),
+                path=Path(prefix, ".condarc"),
+            )
+
         if env.variables:
             prefix_data.set_environment_env_vars(env.variables)
 

@@ -0,0 +1,19 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* Respect `--platform` option on subsequent environment operations after initial `conda env create` call. (#14949 via #14956)
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>
@@ -326,3 +326,49 @@ def test_create_env_from_non_existent_plugin(
             "You have chosen an unrecognized environment specifier type (nonexistent_plugin)"
             in str(excinfo.value)
         )
+
+
+def test_create_env_custom_platform(
+    conda_cli: CondaCLIFixture,
+    tmp_env: TmpEnvFixture,
+    path_factory: PathFactoryFixture,
+    test_recipes_channel: str,
+):
+    """
+    Ensures that the `--platform` option works correctly when creating an environment by
+    creating a `.condarc` file with `subir: osx-64`.
+    """
+    env_file = path_factory("test_recipes_channel.yml")
+    env_file.write_text(
+        f"""
+        name: test-env
+        channels:
+          - {test_recipes_channel}
+        dependencies:
+          - dependency
+        """
+    )
+
+    if context._native_subdir() == "osx-arm64":
+        platform = "linux-64"
+    else:
+        platform = "osx-arm64"
+
+    with tmp_env() as prefix:
+        conda_cli(
+            "env",
+            "create",
+            f"--prefix={prefix}",
+            "--file",
+            str(env_file),
+            f"--platform={platform}",
+        )
+        prefix_data = PrefixData(prefix)
+
+        assert prefix_data.exists()
+        assert prefix_data.is_environment()
+
+        config = prefix / ".condarc"
+
+        assert config.is_file()
+        assert f"subdir: {platform}" in config.read_text()