<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/56803>56803</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [C++20] [Modules] `-fprebuilt-module-path` doesn't work under `-std=c++2b`
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang:driver,
            clang:modules
      </td>
    </tr>

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

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

<pre>
    It is easy to reproduce. Just change the language standard option to `-std=c++2b -fprebuilt-module-path=.`. Then the compiler would warning for:
```
warning: argument unused during compilation: '-fprebuilt-module-path=.' [-Wunused-command-line-argument]
```
</pre>
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