Isolate conda python from site packages, like venv does by default

recipes/conda-create-no-user-site/LICENSE.txt

@@ -0,0 +1,13 @@
+BSD 3-clause license
+Copyright (c) 2015-2022, conda-forge contributors
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

recipes/conda-create-no-user-site/conda_create_no_user_site/__init__.py

@@ -0,0 +1,23 @@
+from pathlib import Path
+
+from conda import plugins
+from conda.base.context import context
+from conda.core.prefix_data import PrefixData
+
+
+def action(argv: list) -> None:
+    target_prefix = context.target_prefix
+    python = PrefixData(target_prefix).get("python", None)
+    if python:
+        pyvenv_cfg = Path(target_prefix, "pyvenv.cfg")
+        with pyvenv_cfg.open("x", encoding="utf-8") as f:
+            f.write("include-system-site-packages = false\n")
+
+
+@plugins.hookimpl
+def conda_post_commands():
+    yield plugins.CondaPostCommand(
+        name="no-user-site",
+        action=action,
+        run_for={"create"},
+    )

recipes/conda-create-no-user-site/meta.yaml

@@ -0,0 +1,44 @@
+package:
+  name: conda-create-no-user-site
+  version: 0.1.0
+
+source:
+  path: .
+
+build:
+  script: {{ PYTHON }} -m pip install . -vv
+  number: 0
+
+requirements:
+  host:
+    - python
+    - pip
+  run:
+    - python
+  run_constrained:
+    - python >=3.3
+
+test:
+  requires:
+    - python
+  commands:
+    - python -c "import sys, site; sys.exit(0 if site.ENABLE_USER_SITE==False else 1)"
+
+about:
+  home: http://conda-forge.org/
+  summary: conda create will configure Python to ignore packages outside the environment
+  description: >
+    This package extends `conda create` to configure Python so it will ignore packages
+    installed with `pip install --user`. Envrionment creation will now add a
+    prefix-level "pyvenv.cfg" file with the line `include-system-site-packages = false`,
+    which gets read by Python's `site` module whenver Python is run. This aligns Python
+    in conda environments with the default behavior of virtual environments created by
+    Python's `venv` module.
+  license: BSD-3-Clause
+  license_family: BSD
+  license_file: LICENSE.txt
+
+extra:
+  recipe-maintainers:
+    - itcarroll
+    - mfansler

recipes/conda-create-no-user-site/pyproject.toml

@@ -0,0 +1,13 @@
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "conda-create-no-user-site"
+version = "0.1.0"
+description = "Create a pyvenv.cfg in an environment created by conda."
+requires-python = ">=3.8"
+dependencies = ["conda"]
+
+[project.entry-points.conda]
+conda-create-no-user-site = "conda_create_no_user_site"