Eliminado venv y www del repositorio, agrege un requirements igual

venv/lib/python3.8/site-packages/pip/_internal/pyproject.py

@@ -3,14 +3,16 @@ from __future__ import absolute_import
 import io
 import os
 import sys
+from collections import namedtuple
 
-from pip._vendor import pytoml, six
+from pip._vendor import six, toml
+from pip._vendor.packaging.requirements import InvalidRequirement, Requirement
 
 from pip._internal.exceptions import InstallationError
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 
 if MYPY_CHECK_RUNNING:
-    from typing import Any, Tuple, Optional, List
+    from typing import Any, Optional, List
 
 
 def _is_list_of_str(obj):
@@ -21,9 +23,9 @@ def _is_list_of_str(obj):
     )
 
 
-def make_pyproject_path(setup_py_dir):
+def make_pyproject_path(unpacked_source_directory):
     # type: (str) -> str
-    path = os.path.join(setup_py_dir, 'pyproject.toml')
+    path = os.path.join(unpacked_source_directory, 'pyproject.toml')
 
     # Python2 __file__ should not be unicode
     if six.PY2 and isinstance(path, six.text_type):
@@ -32,13 +34,18 @@ def make_pyproject_path(setup_py_dir):
     return path
 
 
+BuildSystemDetails = namedtuple('BuildSystemDetails', [
+    'requires', 'backend', 'check', 'backend_path'
+])
+
+
 def load_pyproject_toml(
     use_pep517,  # type: Optional[bool]
     pyproject_toml,  # type: str
     setup_py,  # type: str
     req_name  # type: str
 ):
-    # type: (...) -> Optional[Tuple[List[str], str, List[str]]]
+    # type: (...) -> Optional[BuildSystemDetails]
     """Load the pyproject.toml file.
 
     Parameters:
@@ -56,6 +63,8 @@ def load_pyproject_toml(
             name of PEP 517 backend,
             requirements we should check are installed after setting
                 up the build environment
+            directory paths to import the backend from (backend-path),
+                relative to the project root.
         )
     """
     has_pyproject = os.path.isfile(pyproject_toml)
@@ -63,7 +72,7 @@ def load_pyproject_toml(
 
     if has_pyproject:
         with io.open(pyproject_toml, encoding="utf-8") as f:
-            pp_toml = pytoml.load(f)
+            pp_toml = toml.load(f)
         build_system = pp_toml.get("build-system")
     else:
         build_system = None
@@ -150,7 +159,23 @@ def load_pyproject_toml(
             reason="'build-system.requires' is not a list of strings.",
         ))
 
+    # Each requirement must be valid as per PEP 508
+    for requirement in requires:
+        try:
+            Requirement(requirement)
+        except InvalidRequirement:
+            raise InstallationError(
+                error_template.format(
+                    package=req_name,
+                    reason=(
+                        "'build-system.requires' contains an invalid "
+                        "requirement: {!r}".format(requirement)
+                    ),
+                )
+            )
+
     backend = build_system.get("build-backend")
+    backend_path = build_system.get("backend-path", [])
     check = []  # type: List[str]
     if backend is None:
         # If the user didn't specify a backend, we assume they want to use
@@ -168,4 +193,4 @@ def load_pyproject_toml(
         backend = "setuptools.build_meta:__legacy__"
         check = ["setuptools>=40.8.0", "wheel"]
 
-    return (requires, backend, check)
+    return BuildSystemDetails(requires, backend, check, backend_path)