Warn if a path in PATH starts with tilde during install

news/6414.feature

@@ -0,0 +1 @@
+Warn if a path in PATH starts with tilde during ``pip install``.

src/pip/_internal/wheel.py

@@ -210,6 +210,17 @@ def message_about_scripts_not_on_PATH(scripts):
     else:
         msg_lines.append(last_line_fmt.format("these directories"))
 
+    # Add a note if any directory starts with ~
+    warn_for_tilde = any(
+        i[0] == "~" for i in os.environ.get("PATH", "").split(os.pathsep) if i
+    )
+    if warn_for_tilde:
+        tilde_warning_msg = (
+            "NOTE: The current PATH contains path(s) starting with `~`, "
+            "which may not be expanded by all applications."
+        )
+        msg_lines.append(tilde_warning_msg)
+
     # Returns the formatted multiline message
     return "\n".join(msg_lines)
 

tests/unit/test_wheel.py

@@ -524,6 +524,11 @@ def test_dist_info_contains_empty_dir(self, data, tmpdir):
 
 class TestMessageAboutScriptsNotOnPATH(object):
 
+    tilde_warning_msg = (
+        "NOTE: The current PATH contains path(s) starting with `~`, "
+        "which may not be expanded by all applications."
+    )
+
     def _template(self, paths, scripts):
         with patch.dict('os.environ', {'PATH': os.pathsep.join(paths)}):
             return wheel.message_about_scripts_not_on_PATH(scripts)
@@ -543,6 +548,7 @@ def test_single_script__single_dir_not_on_PATH(self):
         assert retval is not None
         assert "--no-warn-script-location" in retval
         assert "foo is installed in '/c/d'" in retval
+        assert self.tilde_warning_msg not in retval
 
     def test_two_script__single_dir_not_on_PATH(self):
         retval = self._template(
@@ -552,6 +558,7 @@ def test_two_script__single_dir_not_on_PATH(self):
         assert retval is not None
         assert "--no-warn-script-location" in retval
         assert "baz and foo are installed in '/c/d'" in retval
+        assert self.tilde_warning_msg not in retval
 
     def test_multi_script__multi_dir_not_on_PATH(self):
         retval = self._template(
@@ -562,6 +569,7 @@ def test_multi_script__multi_dir_not_on_PATH(self):
         assert "--no-warn-script-location" in retval
         assert "bar, baz and foo are installed in '/c/d'" in retval
         assert "spam is installed in '/a/b/c'" in retval
+        assert self.tilde_warning_msg not in retval
 
     def test_multi_script_all__multi_dir_not_on_PATH(self):
         retval = self._template(
@@ -575,6 +583,7 @@ def test_multi_script_all__multi_dir_not_on_PATH(self):
         assert "--no-warn-script-location" in retval
         assert "bar, baz and foo are installed in '/c/d'" in retval
         assert "eggs and spam are installed in '/a/b/c'" in retval
+        assert self.tilde_warning_msg not in retval
 
     def test_two_script__single_dir_on_PATH(self):
         retval = self._template(
@@ -613,6 +622,7 @@ def test_PATH_check_case_insensitive_on_windows(self):
             assert retval is None
         else:
             assert retval is not None
+            assert self.tilde_warning_msg not in retval
 
     def test_trailing_ossep_removal(self):
         retval = self._template(
@@ -634,6 +644,42 @@ def test_missing_PATH_env_treated_as_empty_PATH_env(self):
 
         assert retval_missing == retval_empty
 
+    def test_no_script_tilde_in_path(self):
+        retval = self._template(
+            paths=['/a/b', '/c/d/bin', '~/e', '/f/g~g'],
+            scripts=[]
+        )
+        assert retval is None
+
+    def test_multi_script_all_tilde__multi_dir_not_on_PATH(self):
+        retval = self._template(
+            paths=['/a/b', '/c/d/bin', '~e/f'],
+            scripts=[
+                '/c/d/foo', '/c/d/bar', '/c/d/baz',
+                '/a/b/c/spam', '/a/b/c/eggs', '/e/f/tilde'
+            ]
+        )
+        assert retval is not None
+        assert "--no-warn-script-location" in retval
+        assert "bar, baz and foo are installed in '/c/d'" in retval
+        assert "eggs and spam are installed in '/a/b/c'" in retval
+        assert "tilde is installed in '/e/f'" in retval
+        assert self.tilde_warning_msg in retval
+
+    def test_multi_script_all_tilde_not_at_start__multi_dir_not_on_PATH(self):
+        retval = self._template(
+            paths=['/e/f~f', '/c/d/bin'],
+            scripts=[
+                '/c/d/foo', '/c/d/bar', '/c/d/baz',
+                '/e/f~f/c/spam', '/e/f~f/c/eggs'
+            ]
+        )
+        assert retval is not None
+        assert "--no-warn-script-location" in retval
+        assert "bar, baz and foo are installed in '/c/d'" in retval
+        assert "eggs and spam are installed in '/e/f~f/c'" in retval
+        assert self.tilde_warning_msg not in retval
+
 
 class TestWheelHashCalculators(object):