From b97ef609100fbdd5895dab48cdab578dfeba396c Mon Sep 17 00:00:00 2001
From: Lumir Balhar <lbalhar@redhat.com>
Date: Fri, 10 Sep 2021 13:38:40 +0200
Subject: [PATCH 1/2] Implement handling of yanked_reason from the HTML anchor

---
 pip/index.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/pip/index.py b/pip/index.py
index f653f6e6a..ced52ce5a 100644
--- a/pip/index.py
+++ b/pip/index.py
@@ -865,7 +865,11 @@ class HTMLPage(object):
                 )
                 pyrequire = anchor.get('data-requires-python')
                 pyrequire = unescape(pyrequire) if pyrequire else None
-                yield Link(url, self, requires_python=pyrequire)
+                yanked_reason = anchor.get('data-yanked', default=None)
+                # Empty or valueless attribute are both parsed as empty string
+                if yanked_reason is not None:
+                    yanked_reason = unescape(yanked_reason)
+                yield Link(url, self, requires_python=pyrequire, yanked_reason=yanked_reason)
 
     _clean_re = re.compile(r'[^a-z0-9$&+,/:;=?@.#%_\\|-]', re.I)
 
@@ -879,7 +883,7 @@ class HTMLPage(object):
 
 class Link(object):
 
-    def __init__(self, url, comes_from=None, requires_python=None):
+    def __init__(self, url, comes_from=None, requires_python=None, yanked_reason=None):
         """
         Object representing a parsed link from https://pypi.python.org/simple/*
 
@@ -900,6 +904,8 @@ class Link(object):
         self.url = url
         self.comes_from = comes_from
         self.requires_python = requires_python if requires_python else None
+        self.yanked_reason = yanked_reason
+        self.yanked = yanked_reason is not None
 
     def __str__(self):
         if self.requires_python:
-- 
2.31.1

From d8dc6ee5d6809736dce43dc1e57d497f9ff91f26 Mon Sep 17 00:00:00 2001
From: Lumir Balhar <lbalhar@redhat.com>
Date: Fri, 10 Sep 2021 13:43:22 +0200
Subject: [PATCH 2/2] Skip all yanked candidates if possible

---
 pip/index.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/pip/index.py b/pip/index.py
index ced52ce5a..823bbaf7d 100644
--- a/pip/index.py
+++ b/pip/index.py
@@ -489,6 +489,27 @@ class PackageFinder(object):
         if applicable_candidates:
             best_candidate = max(applicable_candidates,
                                  key=self._candidate_sort_key)
+            # If we cannot find a non-yanked candidate,
+            # use the best one and print a warning about it.
+            # Otherwise, try to find another best candidate, ignoring
+            # all the yanked releases.
+            if getattr(best_candidate.location, "yanked", False):
+                nonyanked_candidates = [
+                    c for c in applicable_candidates
+                    if not getattr(c.location, "yanked", False)
+                ]
+
+                if set(nonyanked_candidates):
+                    best_candidate = max(nonyanked_candidates,
+                                         key=self._candidate_sort_key)
+                else:
+                    warning_message = (
+                        "WARNING: The candidate selected for download or install "
+                        "is a yanked version: '{}' candidate (version {} at {})"
+                    ).format(best_candidate.project, best_candidate.version, best_candidate.location)
+                    if best_candidate.location.yanked_reason:
+                        warning_message += "\nReason for being yanked: {}".format(best_candidate.location.yanked_reason)
+                    logger.warning(warning_message)
         else:
             best_candidate = None
 
-- 
2.31.1