Changed-lines coverage:
  PR changed C/C++ lines covered by tests: 78.05% (32/41)

Uncovered changed code (with context):

================================================================================
src/Storages/MergeTree/DataPartStorageOnDiskBase.cpp
================================================================================

--- uncovered block 141-145 ---
      139 |     /// guard only looks at our own disk. Fail closed instead, or a name taken on another disk would
      140 |     /// produce a second directory under the same name in a table-wide namespace.
>>    141 |     if (name_taken_anywhere)
>>    142 |         throw Exception(ErrorCodes::DIRECTORY_ALREADY_EXISTS,
>>    143 |                         "Cannot find a free directory name to detach to, last tried: {}", res);
      144 | 
>>    145 |     return res;
      146 | }
      147 | 
================================================================================
src/Storages/MergeTree/IMergeTreeDataPart.cpp
================================================================================

--- uncovered block 2666-2675 ---
     2664 |     catch (const Exception & e)
     2665 |     {
>>   2666 |         if (ignore_error && e.code() == ErrorCodes::DIRECTORY_ALREADY_EXISTS)
     2667 |         {
     2668 |             // A background or startup detach that cannot pick a usable name must be logged and
     2669 |             // skipped, not escalated: some of these callers terminate the server on an exception.
     2670 |             // Only that one code is tolerated: the block also covers the rename itself, and
     2671 |             // swallowing a storage failure there would forget the part while it is still in place.
>>   2672 |             tryLogCurrentException(__PRETTY_FUNCTION__);
     2673 |         }
     2674 |         else
>>   2675 |             throw;
     2676 |     }
     2677 |     part_is_probably_removed_from_disk = true;
================================================================================
src/Storages/MergeTree/MergeTreeData.cpp
================================================================================

--- uncovered block 10722-10725 ---
    10720 |         /// push a live part to a '_tryN' directory that the very same enumeration then filters out.
    10721 |         if (disk->isReadOnly() || disk->isWriteOnce())
>>  10722 |             continue;
    10723 | 
    10724 |         if (disk->existsDirectory(fs::path(relative_data_path) / DETACHED_DIR_NAME / dir_name))
>>  10725 |             return true;
    10726 |     }
    10727 | 
WARNING: Failed to get start time for [Print Uncovered Code] - start time and duration won't be set

--- Coverage counts ---
Lines     : baseline 934,210/1,079,618  ->  current 934,043/1,079,646  (delta -167 / +28)
Functions : baseline 805,658/876,857  ->  current 805,669/876,859  (delta +11 / +2)
Branches  : baseline 305,817/388,428  ->  current 305,753/388,452  (delta -64 / +24)