From 7bb613c1e881a0a9d8725ce6ababaa98917fd0eb Mon Sep 17 00:00:00 2001
From: Krzysztof Konopko <kkonopko@users.noreply.github.com>
Date: Mon, 15 Jun 2020 19:28:46 +0200
Subject: [PATCH] bpo-40448: ensurepip: Do not use cache (GH-19812)

ensurepip optionally installs or upgrades 'pip' and 'setuptools' using
the version of those modules bundled with Python.  The internal PIP
installation routine by default temporarily uses its cache, if it
exists.  This is undesirable as Python builds and installations may be
independent of the user running the build, whilst PIP cache location
is dependent on the user's environment and outside of the build
environment.

At the same time, there's no value in using the cache while installing
bundled modules.

This change disables PIP caching when used in ensurepip.
(cherry picked from commit 4a3a682b12f93a03888e8b59f439bc5fe30d6055)

Co-authored-by: Krzysztof Konopko <kkonopko@users.noreply.github.com>
---
 Lib/ensurepip/__init__.py                        |  2 +-
 Lib/test/test_ensurepip.py                       | 16 ++++++++--------
 Misc/ACKS                                        |  1 +
 .../2020-06-15-12-22-53.bpo-40448.1dk8Bu.rst     |  2 ++
 4 files changed, 12 insertions(+), 9 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2020-06-15-12-22-53.bpo-40448.1dk8Bu.rst

diff --git a/Lib/ensurepip/__init__.py b/Lib/ensurepip/__init__.py
index 566fb2a096bcfe9..ecfaee5640ea980 100644
--- a/Lib/ensurepip/__init__.py
+++ b/Lib/ensurepip/__init__.py
@@ -116,7 +116,7 @@ def _bootstrap(*, root=None, upgrade=False, user=False,
             additional_paths.append(os.path.join(tmpdir, wheel_name))
 
         # Construct the arguments to be passed to the pip command
-        args = ["install", "--no-index", "--find-links", tmpdir]
+        args = ["install", "--no-cache-dir", "--no-index", "--find-links", tmpdir]
         if root:
             args += ["--root", root]
         if upgrade:
diff --git a/Lib/test/test_ensurepip.py b/Lib/test/test_ensurepip.py
index 89966893092851c..4786d28f39a3d04 100644
--- a/Lib/test/test_ensurepip.py
+++ b/Lib/test/test_ensurepip.py
@@ -40,7 +40,7 @@ def test_basic_bootstrapping(self):
 
         self.run_pip.assert_called_once_with(
             [
-                "install", "--no-index", "--find-links",
+                "install", "--no-cache-dir", "--no-index", "--find-links",
                 unittest.mock.ANY, "setuptools", "pip",
             ],
             unittest.mock.ANY,
@@ -54,7 +54,7 @@ def test_bootstrapping_with_root(self):
 
         self.run_pip.assert_called_once_with(
             [
-                "install", "--no-index", "--find-links",
+                "install", "--no-cache-dir", "--no-index", "--find-links",
                 unittest.mock.ANY, "--root", "/foo/bar/",
                 "setuptools", "pip",
             ],
@@ -66,7 +66,7 @@ def test_bootstrapping_with_user(self):
 
         self.run_pip.assert_called_once_with(
             [
-                "install", "--no-index", "--find-links",
+                "install", "--no-cache-dir", "--no-index", "--find-links",
                 unittest.mock.ANY, "--user", "setuptools", "pip",
             ],
             unittest.mock.ANY,
@@ -77,7 +77,7 @@ def test_bootstrapping_with_upgrade(self):
 
         self.run_pip.assert_called_once_with(
             [
-                "install", "--no-index", "--find-links",
+                "install", "--no-cache-dir", "--no-index", "--find-links",
                 unittest.mock.ANY, "--upgrade", "setuptools", "pip",
             ],
             unittest.mock.ANY,
@@ -88,7 +88,7 @@ def test_bootstrapping_with_verbosity_1(self):
 
         self.run_pip.assert_called_once_with(
             [
-                "install", "--no-index", "--find-links",
+                "install", "--no-cache-dir", "--no-index", "--find-links",
                 unittest.mock.ANY, "-v", "setuptools", "pip",
             ],
             unittest.mock.ANY,
@@ -99,7 +99,7 @@ def test_bootstrapping_with_verbosity_2(self):
 
         self.run_pip.assert_called_once_with(
             [
-                "install", "--no-index", "--find-links",
+                "install", "--no-cache-dir", "--no-index", "--find-links",
                 unittest.mock.ANY, "-vv", "setuptools", "pip",
             ],
             unittest.mock.ANY,
@@ -110,7 +110,7 @@ def test_bootstrapping_with_verbosity_3(self):
 
         self.run_pip.assert_called_once_with(
             [
-                "install", "--no-index", "--find-links",
+                "install", "--no-cache-dir", "--no-index", "--find-links",
                 unittest.mock.ANY, "-vvv", "setuptools", "pip",
             ],
             unittest.mock.ANY,
@@ -260,7 +260,7 @@ def test_basic_bootstrapping(self):
 
         self.run_pip.assert_called_once_with(
             [
-                "install", "--no-index", "--find-links",
+                "install", "--no-cache-dir", "--no-index", "--find-links",
                 unittest.mock.ANY, "setuptools", "pip",
             ],
             unittest.mock.ANY,
diff --git a/Misc/ACKS b/Misc/ACKS
index e85e370c98cc794..8098637a32c5d9d 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -885,6 +885,7 @@ Vajrasky Kok
 Guido Kollerie
 Jacek Kołodziej
 Jacek Konieczny
+Krzysztof Konopko
 Arkady Koplyarov
 Peter A. Koren
 Марк Коренберг
diff --git a/Misc/NEWS.d/next/Library/2020-06-15-12-22-53.bpo-40448.1dk8Bu.rst b/Misc/NEWS.d/next/Library/2020-06-15-12-22-53.bpo-40448.1dk8Bu.rst
new file mode 100644
index 000000000000000..a755c5faa671c33
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-06-15-12-22-53.bpo-40448.1dk8Bu.rst
@@ -0,0 +1,2 @@
+:mod:`ensurepip` now disables the use of `pip` cache when installing the
+bundled versions of `pip` and `setuptools`.  Patch by Krzysztof Konopko.