Allow non lowercase extras

news/4617.bugfix

@@ -0,0 +1 @@
+Fix bug that prevents pip from installing extras with names containing upper-case letters.

src/pip/_internal/req/req_install.py

@@ -14,7 +14,7 @@
 
 from pip._vendor import pkg_resources, six
 from pip._vendor.packaging import specifiers
-from pip._vendor.packaging.markers import Marker
+from pip._vendor.packaging.markers import Marker, UndefinedEnvironmentName
 from pip._vendor.packaging.requirements import InvalidRequirement, Requirement
 from pip._vendor.packaging.utils import canonicalize_name
 from pip._vendor.packaging.version import parse as parse_version
@@ -712,15 +712,22 @@ def _clean_zip_name(self, name, prefix):
         name = name.replace(os.path.sep, '/')
         return name
 
-    def match_markers(self, extras_requested=None):
-        if not extras_requested:
-            # Provide an extra to safely evaluate the markers
-            # without matching any extra
-            extras_requested = ('',)
+    def match_markers(self):
+
         if self.markers is not None:
-            return any(
-                self.markers.evaluate({'extra': extra})
-                for extra in extras_requested)
+
+            # In certain situations,
+            # the parsing and evaluation of extra markers is unreliable.
+            # By the time this code is executed,
+            #  the existence of necessary extras
+            # has already been reliably determined.
+            # try/except clause forces extra marker to evaluate as True,
+            # avoiding incorrect and unnecessary evaluations.
+
+            try:
+                return self.markers.evaluate()
+            except UndefinedEnvironmentName:
+                return True
         else:
             return True
 

src/pip/_internal/req/req_set.py

@@ -48,8 +48,7 @@ def __repr__(self):
         return ('<%s object; %d requirement(s): %s>'
                 % (self.__class__.__name__, len(reqs), reqs_str))
 
-    def add_requirement(self, install_req, parent_req_name=None,
-                        extras_requested=None):
+    def add_requirement(self, install_req, parent_req_name=None):
         """Add install_req as a requirement to install.
 
         :param parent_req_name: The name of the requirement that needed this
@@ -58,14 +57,12 @@ def add_requirement(self, install_req, parent_req_name=None,
             links that point outside the Requirements set. parent_req must
             already be added. Note that None implies that this is a user
             supplied requirement, vs an inferred one.
-        :param extras_requested: an iterable of extras used to evaluate the
-            environement markers.
         :return: Additional requirements to scan. That is either [] if
             the requirement is not applicable, or [install_req] if the
             requirement is applicable and has just been added.
         """
         name = install_req.name
-        if not install_req.match_markers(extras_requested):
+        if not install_req.match_markers():
             logger.warning("Ignoring %s: markers '%s' don't match your "
                            "environment", install_req.name,
                            install_req.markers)

src/pip/_internal/resolve.py

@@ -261,7 +261,7 @@ def _resolve_one(self, requirement_set, req_to_install):
 
         more_reqs = []
 
-        def add_req(subreq, extras_requested):
+        def add_req(subreq):
             sub_install_req = InstallRequirement.from_req(
                 str(subreq),
                 req_to_install,
@@ -271,7 +271,6 @@ def add_req(subreq, extras_requested):
             more_reqs.extend(
                 requirement_set.add_requirement(
                     sub_install_req, req_to_install.name,
-                    extras_requested=extras_requested
                 )
             )
 
@@ -280,7 +279,7 @@ def add_req(subreq, extras_requested):
             # can refer to it when adding dependencies.
             if not requirement_set.has_requirement(req_to_install.name):
                 # 'unnamed' requirements will get added here
-                requirement_set.add_requirement(req_to_install, None)
+                requirement_set.add_requirement(req_to_install)
 
             if not self.ignore_dependencies:
                 if req_to_install.extras:
@@ -301,7 +300,7 @@ def add_req(subreq, extras_requested):
                     set(dist.extras) & set(req_to_install.extras)
                 )
                 for subreq in dist.requires(available_requested):
-                    add_req(subreq, extras_requested=available_requested)
+                    add_req(subreq)
 
             if not req_to_install.editable and not req_to_install.satisfied_by:
                 # XXX: --no-install leads this to report 'Successfully

tests/functional/test_install_extras.py

@@ -1,3 +1,4 @@
+import sys
 import textwrap
 from os.path import join
 
@@ -126,3 +127,22 @@ def test_install_special_extra(script):
     assert (
         "Could not find a version that satisfies the requirement missing_pkg"
     ) in result.stderr, str(result)
+
+
+@pytest.mark.skipif(sys.version_info < (3, 0),
+                    reason="requires Python3")
+@pytest.mark.network
+def test_extras_with_mixed_case_name(script):
+    """
+    Test installing a package
+    """
+    extra_name = 'reST'
+    dependency_with_extra = 'django-rest-swagger[{}]==0.3.10'.format(
+        extra_name
+    )
+    result = script.pip(
+        'install', dependency_with_extra, expect_stderr=True,
+    )
+    template = """markers 'extra == "{}"' don't match your environment"""
+    error_message = template.format(extra_name)
+    assert error_message not in result.stderr