remove corrupt cache files and retry download 3 times

conans/client/downloaders/cached_file_downloader.py

@@ -7,7 +7,8 @@
 
 from conans.client.downloaders.file_downloader import check_checksum
 from conans.errors import ConanException
-from conans.util.files import mkdir, set_dirty, clean_dirty, is_dirty
+from conans.util.log import logger
+from conans.util.files import mkdir, set_dirty, clean_dirty, is_dirty, remove
 from conans.util.locks import SimpleLock
 from conans.util.sha import sha256 as sha256_sum
 
@@ -47,19 +48,27 @@ def download(self, url, file_path=None, md5=None, sha1=None, sha256=None, **kwar
                 if os.path.exists(cached_path):
                     os.remove(cached_path)
                 clean_dirty(cached_path)
-            if not os.path.exists(cached_path):
-                set_dirty(cached_path)
-                self._file_downloader.download(url=url, file_path=cached_path, md5=md5,
-                                               sha1=sha1, sha256=sha256, **kwargs)
-                clean_dirty(cached_path)
-            else:
-                # specific check for corrupted cached files, will raise, but do nothing more
-                # user can report it or "rm -rf cache_folder/path/to/file"
-                try:
-                    check_checksum(cached_path, md5, sha1, sha256)
-                except ConanException as e:
-                    raise ConanException("%s\nCached downloaded file corrupted: %s"
-                                         % (str(e), cached_path))
+
+            for attempt in range(3):
+                if not os.path.exists(cached_path):
+                    set_dirty(cached_path)
+                    self._file_downloader.download(url=url, file_path=cached_path, md5=md5,
+                                                sha1=sha1, sha256=sha256, **kwargs)
+                    clean_dirty(cached_path)
+                else:
+                    # specific check for corrupted cached files, will log an error
+                    # and raise after the third failed download attempt
+                    try:
+                        check_checksum(cached_path, md5, sha1, sha256)
+                        break
+                    except ConanException as e:
+                        if attempt == 2:
+                            raise ConanException("%s\nCached downloaded file corrupted: %s"
+                                                % (str(e), cached_path))
+                        else:
+                            logger.error("Cached file corrupt, redownloading")
+                            remove(cached_path)
+
 
             if file_path is not None:
                 file_path = os.path.abspath(file_path)

conans/test/integration/cache/download_cache_test.py

@@ -93,9 +93,8 @@ def package(self):
                 continue
             save(f, load(f) + "a")
         client.run("remove * -f")
-        client.run("install mypkg/0.1@user/testing", assert_error=True)
-        self.assertIn("ERROR: md5 signature failed", client.out)
-        self.assertIn("Cached downloaded file corrupted", client.out)
+        client.run("install mypkg/0.1@user/testing")
+        self.assertIn("mypkg/0.1@user/testing: Downloaded package", client.out)
 
     @pytest.mark.skipif(not get_env("TESTING_REVISIONS_ENABLED", False), reason="Only revisions")
     def test_dirty_download(self):