Add pip>=20.3 support (#1216)

Co-authored-by: Andy Kluger <andykluger@gmail.com>

.appveyor.yml

@@ -3,28 +3,28 @@ environment:
       PYTHON: "C:\\Python36"
 
     matrix:
-        - TOXENV: py27-pip20.1-coverage
-          PIP: 20.1
+        - TOXENV: py27-pipprevious-coverage
+          PIP: previous
         - TOXENV: py27-piplatest-coverage
           PIP: latest
 
-        - TOXENV: py35-pip20.1
-          PIP: 20.1
+        - TOXENV: py35-pipprevious
+          PIP: previous
         - TOXENV: py35-piplatest
           PIP: latest
 
-        - TOXENV: py36-pip20.1
-          PIP: 20.1
+        - TOXENV: py36-pipprevious
+          PIP: previous
         - TOXENV: py36-piplatest
           PIP: latest
 
-        - TOXENV: py37-pip20.1
-          PIP: 20.1
+        - TOXENV: py37-pipprevious
+          PIP: previous
         - TOXENV: py37-piplatest
           PIP: latest
 
-        - TOXENV: py38-pip20.1-coverage
-          PIP: 20.1
+        - TOXENV: py38-pipprevious-coverage
+          PIP: previous
         - TOXENV: py38-piplatest-coverage
           PIP: latest
 

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
           - 3.7
         pip-version:
           - "latest"
-          - "20.1"
+          - "previous"
         include:
           - os: Ubuntu
             python-version: 3.9-dev

README.rst

@@ -464,5 +464,5 @@ versions.
 +---------------+-----------------+
 | 5.0.0 - 5.3.0 | 20.0 - 20.1.1   |
 +---------------+-----------------+
-| >= 5.4.0      | 20.1 - 20.2.*   |
+| >= 5.4.0      | 20.1 - 20.3.*   |
 +---------------+-----------------+

piptools/repositories/pypi.py

@@ -58,7 +58,12 @@ def __init__(self, pip_args, cache_dir):
         # General options (find_links, index_url, extra_index_url, trusted_host,
         # and pre) are deferred to pip.
         self.command = create_command("install")
-        self.options, _ = self.command.parse_args(pip_args)
+        extra_pip_args = (
+            []
+            if PIP_VERSION[:2] <= (20, 2)
+            else ["--use-deprecated", "legacy-resolver"]
+        )
+        self.options, _ = self.command.parse_args(pip_args + extra_pip_args)
         if self.options.cache_dir:
             self.options.cache_dir = normalize_path(self.options.cache_dir)
 
@@ -85,7 +90,8 @@ def __init__(self, pip_args, cache_dir):
         self.freshen_build_caches()
         self._cache_dir = normalize_path(cache_dir)
         self._download_dir = fs_str(os.path.join(self._cache_dir, "pkgs"))
-        self._wheel_download_dir = fs_str(os.path.join(self._cache_dir, "wheels"))
+        if PIP_VERSION[:2] <= (20, 2):
+            self._wheel_download_dir = fs_str(os.path.join(self._cache_dir, "wheels"))
 
         self._setup_logging()
 
@@ -107,7 +113,8 @@ def source_dir(self):
 
     def clear_caches(self):
         rmtree(self._download_dir, ignore_errors=True)
-        rmtree(self._wheel_download_dir, ignore_errors=True)
+        if PIP_VERSION[:2] <= (20, 2):
+            rmtree(self._wheel_download_dir, ignore_errors=True)
 
     def find_all_candidates(self, req_name):
         if req_name not in self._available_candidates_cache:
@@ -153,16 +160,18 @@ def resolve_reqs(self, download_dir, ireq, wheel_cache):
         with get_requirement_tracker() as req_tracker, TempDirectory(
             kind="resolver"
         ) as temp_dir, indent_log():
-            preparer = self.command.make_requirement_preparer(
+            preparer_kwargs = dict(
                 temp_build_dir=temp_dir,
                 options=self.options,
                 req_tracker=req_tracker,
                 session=self.session,
                 finder=self.finder,
                 use_user_site=False,
                 download_dir=download_dir,
-                wheel_download_dir=self._wheel_download_dir,
             )
+            if PIP_VERSION[:2] <= (20, 2):
+                preparer_kwargs["wheel_download_dir"] = self._wheel_download_dir
+            preparer = self.command.make_requirement_preparer(**preparer_kwargs)
 
             reqset = RequirementSet()
             if PIP_VERSION[:2] <= (20, 1):
@@ -186,7 +195,10 @@ def resolve_reqs(self, download_dir, ireq, wheel_cache):
             if not ireq.prepared:
                 # If still not prepared, e.g. a constraint, do enough to assign
                 # the ireq a name:
-                resolver._get_abstract_dist_for(ireq)
+                if PIP_VERSION[:2] <= (20, 2):
+                    resolver._get_abstract_dist_for(ireq)
+                else:
+                    resolver._get_dist_for(ireq)
 
         return set(results)
 
@@ -219,7 +231,9 @@ def get_dependencies(self, ireq):
                 download_dir = self._get_download_path(ireq)
                 if not os.path.isdir(download_dir):
                     os.makedirs(download_dir)
-            if not os.path.isdir(self._wheel_download_dir):
+            if PIP_VERSION[:2] <= (20, 2) and not os.path.isdir(
+                self._wheel_download_dir
+            ):
                 os.makedirs(self._wheel_download_dir)
 
             with global_tempdir_manager():

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist =
     # NOTE: keep this in sync with the env list in .github/workflows/ci.yml.
-    py{27,35,36,37,38,39,py,py3}-pip{20.1,20.2,latest,master}-coverage
+    py{27,35,36,37,38,39,py,py3}-pip{20.1,20.2,20.3,previous,latest,master}-coverage
     checkqa
     readme
 skip_missing_interpreters = True
@@ -11,14 +11,21 @@ extras =
     testing
     coverage: coverage
 deps =
+    pipprevious: pip==20.2.*
+    # TODO: change to `pip` after pip-20.3 being released
+    piplatest: -e git+https://github.com/pypa/pip.git@master#egg=pip
     pipmaster: -e git+https://github.com/pypa/pip.git@master#egg=pip
     pip20.1: pip==20.1.*
     pip20.2: pip==20.2.*
+    # TODO: change to `pip==20.3.*` after pip-20.3 being released
+    pip20.3: -e git+https://github.com/pypa/pip.git@master#egg=pip
 setenv =
+    pipprevious: PIP=previous
     piplatest: PIP=latest
     pipmaster: PIP=master
     pip20.1: PIP==20.1
     pip20.2: PIP==20.2
+    pip20.3: PIP==20.3
 
     coverage: PYTEST_ADDOPTS=--strict --doctest-modules --cov --cov-report=term-missing --cov-report=xml {env:PYTEST_ADDOPTS:}
 commands_pre =