Add use_user_site to RequirementPreparer

src/pip/_internal/cli/req_command.py

@@ -154,6 +154,7 @@ def make_requirement_preparer(
         req_tracker,              # type: RequirementTracker
         session,                  # type: PipSession
         finder,                   # type: PackageFinder
+        use_user_site,            # type: bool
         download_dir=None,        # type: str
         wheel_download_dir=None,  # type: str
     ):
@@ -174,6 +175,7 @@ def make_requirement_preparer(
             session=session,
             finder=finder,
             require_hashes=options.require_hashes,
+            use_user_site=use_user_site,
         )
 
     @staticmethod

src/pip/_internal/commands/download.py

@@ -132,6 +132,7 @@ def run(self, options, args):
                 session=session,
                 finder=finder,
                 download_dir=options.download_dir,
+                use_user_site=False,
             )
 
             resolver = self.make_resolver(

src/pip/_internal/commands/install.py

@@ -361,6 +361,7 @@ def run(self, options, args):
                     req_tracker=req_tracker,
                     session=session,
                     finder=finder,
+                    use_user_site=options.use_user_site,
                 )
                 resolver = self.make_resolver(
                     preparer=preparer,

src/pip/_internal/commands/wheel.py

@@ -176,6 +176,7 @@ def run(self, options, args):
                     session=session,
                     finder=finder,
                     wheel_download_dir=options.wheel_dir,
+                    use_user_site=False,
                 )
 
                 resolver = self.make_resolver(

src/pip/_internal/legacy_resolve.py

@@ -269,9 +269,7 @@ def _get_abstract_dist_for(self, req):
         representing a prepared variant of the same.
         """
         if req.editable:
-            return self.preparer.prepare_editable_requirement(
-                req, self.use_user_site
-            )
+            return self.preparer.prepare_editable_requirement(req)
 
         # satisfied_by is only evaluated by calling _check_skip_installed,
         # so it must be None here.

src/pip/_internal/operations/prepare.py

@@ -511,6 +511,7 @@ def __init__(
         session,  # type: PipSession
         finder,  # type: PackageFinder
         require_hashes,  # type: bool
+        use_user_site,  # type: bool
     ):
         # type: (...) -> None
         super(RequirementPreparer, self).__init__()
@@ -547,6 +548,9 @@ def __init__(
         # Should hash-checking be required?
         self.require_hashes = require_hashes
 
+        # Should install in user site-packages?
+        self.use_user_site = use_user_site
+
     @property
     def _download_should_save(self):
         # type: () -> bool
@@ -682,7 +686,6 @@ def prepare_linked_requirement(
     def prepare_editable_requirement(
         self,
         req,  # type: InstallRequirement
-        use_user_site,  # type: bool
     ):
         # type: (...) -> AbstractDistribution
         """Prepare an editable requirement
@@ -707,7 +710,7 @@ def prepare_editable_requirement(
 
             if self._download_should_save:
                 req.archive(self.download_dir)
-            req.check_if_exists(use_user_site)
+            req.check_if_exists(self.use_user_site)
 
         return abstract_dist
 

tests/unit/test_req.py

@@ -83,6 +83,7 @@ def _basic_resolver(self, finder, require_hashes=False):
                 session=PipSession(),
                 finder=finder,
                 require_hashes=require_hashes,
+                use_user_site=False,
             )
             yield Resolver(
                 preparer=preparer,