Remove PIP_REQUIRE_VIRTUALENV from environment when invoking pip

Fixes pypa#90.
adamchainz · Sep 10, 2020 · d1e9df0 · d1e9df0
1 parent 10bf02e
commit d1e9df0
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Showing 2 changed files with 35 additions and 10 deletions.
diff --git a/src/build/env.py b/src/build/env.py
@@ -169,9 +169,18 @@ def install(self, requirements):  # type: (Iterable[str]) -> None
         with tempfile.NamedTemporaryFile('w+', prefix='build-reqs-', suffix='.txt', delete=False) as req_file:
             req_file.write(os.linesep.join(requirements))
             req_file.close()
-            cmd = [
-                sys.executable, '-m', 'pip', 'install', '--prefix',
-                self.path, '-r', os.path.abspath(req_file.name)
-            ]
-            subprocess.check_call(cmd)
-            os.unlink(req_file.name)
+
+            try:
+                cmd = [
+                    sys.executable, '-m', 'pip', 'install', '--prefix',
+                    self.path, '-r', os.path.abspath(req_file.name)
+                ]
+                env = os.environ.copy()
+                # Allow pip to operate without an active virtualenv
+                env.pop("PIP_REQUIRE_VIRTUALENV", None)
+
+                retcode = subprocess.Popen(cmd, env=env).wait()
+                if retcode != 0:
+                    raise subprocess.CalledProcessError(retcode, cmd)
+            finally:
+                os.unlink(req_file.name)
diff --git a/tests/test_env.py b/tests/test_env.py
@@ -10,7 +10,7 @@
 import build.env
 
 
-def test_isolated_environment_setup(mocker):
+def test_isolated_environment_setup():
     old_path = os.environ['PATH']
     with build.env.IsolatedEnvironment.for_current() as env:
         if os.name != 'nt':
@@ -56,19 +56,35 @@ def test_isolated_environment_setup(mocker):
 def test_isolated_environment_install(mocker):
     with build.env.IsolatedEnvironment.for_current() as env:
         mocker.patch('subprocess.check_call')
+        mocker.patch('subprocess.Popen')
+        subprocess.Popen.return_value.wait.return_value = 0
 
         env.install([])
-        subprocess.check_call.assert_not_called()
+        subprocess.Popen.assert_not_called()
 
         env.install(['some', 'requirements'])
         if sys.version_info[:2] != (3, 5):
-            subprocess.check_call.assert_called()
-        args = subprocess.check_call.call_args[0][0]
+            subprocess.Popen.assert_called()
+        args = subprocess.Popen.call_args[0][0]
         assert args[:7] == [
             sys.executable, '-m', 'pip', 'install', '--prefix', env.path, '-r'
         ]
 
 
+def test_isolated_environment_install_no_require_virtualenv(mocker):
+    with build.env.IsolatedEnvironment.for_current() as env:
+        mocker.patch('subprocess.check_call')
+        mocker.patch('subprocess.Popen')
+        subprocess.Popen.return_value.wait.return_value = 0
+        mocker.patch.dict(os.environ, {"PIP_REQUIRE_VIRTUALENV": "true"})
+
+        env.install(['some', 'requirements'])
+        if sys.version_info[:2] != (3, 5):
+            subprocess.Popen.assert_called()
+        env = subprocess.Popen.call_args[1]
+        assert "PIP_REQUIRE_VIRTUALENV" not in env
+
+
 def test_uninitialised_isolated_environment():
     env = build.env.IsolatedEnvironment.for_current()