From efe32727c68db99aea8b2c3efd8fcc8f9b52178f Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Thu, 22 Jun 2023 04:47:19 +0200
Subject: [PATCH 1/3] Revert "Add pip as test requirement for PEP 660 editable
 installs (#15482)"

This reverts commit 7d031beb017450ac990c97e288d064290e3be55f.
---
 test-requirements.txt | 1 -
 1 file changed, 1 deletion(-)

diff --git a/test-requirements.txt b/test-requirements.txt
index 8aea01f9e996..51cd62d4064c 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -5,7 +5,6 @@ black==23.3.0  # must match version in .pre-commit-config.yaml
 filelock>=3.3.0
 isort[colors]==5.12.0; python_version >= "3.8"   # must match version in .pre-commit-config.yaml
 lxml>=4.9.1; (python_version<'3.11' or sys_platform!='win32') and python_version<'3.12'
-pip>=21.3.1
 pre-commit
 pre-commit-hooks==4.4.0
 psutil>=4.0

From 2efac0dbbe9d5430c8617f75b7f855695a20b7a0 Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Thu, 22 Jun 2023 04:46:32 +0200
Subject: [PATCH 2/3] Fix PEP 561 - editable install - test case

---
 mypy/test/testpep561.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/mypy/test/testpep561.py b/mypy/test/testpep561.py
index b8a11d7fc8af..bacbcca4ebb2 100644
--- a/mypy/test/testpep561.py
+++ b/mypy/test/testpep561.py
@@ -46,6 +46,18 @@ def virtualenv(python_executable: str = sys.executable) -> Iterator[tuple[str, s
             yield venv_dir, os.path.abspath(os.path.join(venv_dir, "bin", "python"))
 
 
+def upgrade_pip(python_executable: str, version_str: str) -> None:
+    """Install a newer pip version."""
+    install_cmd = [python_executable, "-m", "pip", "install", f"pip{version_str}"]
+    try:
+        with filelock.FileLock(pip_lock, timeout=pip_timeout):
+            proc = subprocess.run(install_cmd, capture_output=True, env=os.environ)
+    except filelock.Timeout as err:
+        raise Exception(f"Failed to acquire {pip_lock}") from err
+    if proc.returncode != 0:
+        raise Exception(proc.stdout.decode("utf-8") + proc.stderr.decode("utf-8"))
+
+
 def install_package(
     pkg: str, python_executable: str = sys.executable, editable: bool = False
 ) -> None:
@@ -93,6 +105,9 @@ def test_pep561(testcase: DataDrivenTestCase) -> None:
     assert pkgs, "No packages to install for PEP 561 test?"
     with virtualenv(python) as venv:
         venv_dir, python_executable = venv
+        if editable:
+            # Editable installs with PEP 660 require pip>=21.3
+            upgrade_pip(python_executable, ">=21.3.1")
         for pkg in pkgs:
             install_package(pkg, python_executable, editable)
 

From 2e098dea19982ca9ed1dc290edb019b4f0c7d5a6 Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Thu, 22 Jun 2023 11:27:05 +0200
Subject: [PATCH 3/3] Performance improvements

---
 mypy/test/testpep561.py | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/mypy/test/testpep561.py b/mypy/test/testpep561.py
index bacbcca4ebb2..da5025faef03 100644
--- a/mypy/test/testpep561.py
+++ b/mypy/test/testpep561.py
@@ -46,9 +46,19 @@ def virtualenv(python_executable: str = sys.executable) -> Iterator[tuple[str, s
             yield venv_dir, os.path.abspath(os.path.join(venv_dir, "bin", "python"))
 
 
-def upgrade_pip(python_executable: str, version_str: str) -> None:
-    """Install a newer pip version."""
-    install_cmd = [python_executable, "-m", "pip", "install", f"pip{version_str}"]
+def upgrade_pip(python_executable: str) -> None:
+    """Install pip>=21.3.1. Required for editable installs with PEP 660."""
+    if (
+        sys.version_info >= (3, 11)
+        or (3, 10, 3) <= sys.version_info < (3, 11)
+        or (3, 9, 11) <= sys.version_info < (3, 10)
+        or (3, 8, 13) <= sys.version_info < (3, 9)
+    ):
+        # Skip for more recent Python releases which come with pip>=21.3.1
+        # out of the box - for performance reasons.
+        return
+
+    install_cmd = [python_executable, "-m", "pip", "install", "pip>=21.3.1"]
     try:
         with filelock.FileLock(pip_lock, timeout=pip_timeout):
             proc = subprocess.run(install_cmd, capture_output=True, env=os.environ)
@@ -107,7 +117,7 @@ def test_pep561(testcase: DataDrivenTestCase) -> None:
         venv_dir, python_executable = venv
         if editable:
             # Editable installs with PEP 660 require pip>=21.3
-            upgrade_pip(python_executable, ">=21.3.1")
+            upgrade_pip(python_executable)
         for pkg in pkgs:
             install_package(pkg, python_executable, editable)