null out pythonpath (#252)

* fixes #233

docs/changelog.md

@@ -2,6 +2,7 @@ dev
 
 - Handle missing interpreters more gracefully (#146)
 - Change `reinstall-all` to use system python by default for apps.  Now use `--python` option to specify a different python version.
+- Remove the PYTHONPATH environment variable when executing any command to prevent conflicts between pipx dependencies and package dependenies when pipx is installed via homebrew. Homebrew can use pythonpath manipulation instead of virtual environments. (#233)
 
 0.14.0.0
 

src/pipx/main.py

@@ -20,7 +20,7 @@
 from .util import PipxError, mkdir
 from .venv import VenvContainer
 
-__version__ = "0.14.0.0"
+__version__ = "0.14.0.1"
 
 
 def simple_parse_version(s, segments=4) -> Tuple[Union[int, str], ...]:

src/pipx/util.py

@@ -94,11 +94,12 @@ def get_site_packages(python: Path) -> Path:
 def run(cmd: Sequence[Union[str, Path]], check=True) -> int:
     """Run arbitrary command as subprocess"""
 
+    env = {k: v for k, v in os.environ.items() if k.upper() != "PYTHONPATH"}
     cmd_str = " ".join(str(c) for c in cmd)
     logging.info(f"running {cmd_str}")
     # windows cannot take Path objects, only strings
     cmd_str_list = [str(c) for c in cmd]
-    returncode = subprocess.run(cmd_str_list).returncode
+    returncode = subprocess.run(cmd_str_list, env=env).returncode
     if check and returncode:
         raise PipxError(f"{cmd_str!r} failed")
     return returncode

tests/test_run.py

@@ -1,6 +1,8 @@
 #!/usr/bin/env python3
+import os
 import logging
 import sys
+import subprocess
 from unittest import mock
 
 import pytest  # type: ignore
@@ -42,3 +44,26 @@ def test_run_script_from_internet(pipx_temp_env, capsys):
             "6bdfbb6e9c1132b1c38fdd2f195d4a24c540c324/pipx-demo.py",
         ]
     )
+
+
+def test_run_ensure_null_pythonpath():
+    env = os.environ.copy()
+    env["PYTHONPATH"] = "test"
+    assert (
+        "None"
+        in subprocess.run(
+            [
+                sys.executable,
+                "-m",
+                "pipx",
+                "run",
+                "ipython",
+                "-c",
+                "import os; print(os.environ.get('PYTHONPATH'))",
+            ],
+            universal_newlines=True,
+            env=env,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        ).stdout
+    )