<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/56024>56024</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Duplicated diagnostic message "must be imported ... before it is used"
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          ChuanqiXu9
      </td>
    </tr>
</table>

<pre>
    In  https://github.com/llvm/llvm-project/blob/16ca490f450ea3ceaeda92addd8546967af4b2e1/clang/test/Modules/cxx-templates.cpp#L215-L232 , we could find many 'expected-error +1' directives. And if we remove the '+1' part, we could find many duplicated error message. It is not user friendly. 

Note that there is a FIXME in https://github.com/llvm/llvm-project/blob/16ca490f450ea3ceaeda92addd8546967af4b2e1/clang/lib/Sema/SemaLookup.cpp#L5446-L5447, I guess they refer to the same thing.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJy9kk2PmzAQhn8NXKwgMIaEA4fspitFyvbSy17HeAC3BlN_pJt_33G20Z566KUS8mi-33mEtOrWn1fG5hA2n9XHjL_QN-kwR1kMdiHHmOvD7DZnv-MQyJXGSjJVO4DoylE0JUI9IKCCjoNS6tCItmv3MArJsaLSwcA6kQ3o04BXq6JBnxLv77uAy2aAUsWwbRmvL7xqdhdec5bxZ_YL2WCjUWzUq2ILrDcK7_F9Iy2oduicdRR5ojV7prSjsL7SLHakcj2mfoeLvSILM6bWR-0GLvxlgYqb0QNJUuxj_oLew4QFOwemPVttYNGjY6PTuCpzK1hWnrLy-PF-tSFtg5BWOkwdwF7Ob69fmF7_J26jU-M3XOCPuVj7I24Pzo0Q7S69-8ThzKZIZybNN0I20nnB3qF5WNI9ep2KXPW16uoO8qCDwf70SUppmFbrgx4euIg2X6IPTBKDZbMulRVFQf5oE5c7TAKpqDCPzvT_zEZ7H-8_UtOWXORzL0COw_6Ah7YZy6aG4cCHSopaIsgDF5gbkGh8nzVPWXPKdc9Lzsu2EmVbV6ItqlF2eICxVLKUileZKImbNkVaXFg35a6_a5Bx8pQ02gf_mQTv9bQiPuZDDLN1_fMcYf2p32KX3xX3d7m_AXIiIlQ">