<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/114591>114591</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [libcxx] cannot build with clang++ --target=x86_64-windows-msvc
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang,
            libc++
      </td>
    </tr>

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

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

<pre>
    ```
-- Performing Test CXX_SUPPORTS_WNO_ERROR_FLAG
-- Performing Test CXX_SUPPORTS_WNO_ERROR_FLAG - Failed
-- Performing Test CXX_SUPPORTS_EHSC_FLAG
-- Performing Test CXX_SUPPORTS_EHSC_FLAG - Failed
-- Configuring done (11.3s)
CMake Error in /home/csrg/toolchains_build/llvm-project/libcxx/src/CMakeLists.txt:
  No known features for CXX compiler

  "Clang"

  version 20.0.0.


CMake Generate step failed.  Build files cannot be regenerated correctly.
runtimesconfigure build failure
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJycU01vnDAU_DXm8gSCB_vBgUOyG9JDmkSbVM1tZcwD3Bh7ZZvdzb-vYEmUKpe2whfkeTOaN2PunGw1UcEW12yxDfjgO2MLb4V10lIdVKZ-K9gynk-8ZfFVGMIj2cbYXuoWnsl52Ly87J9-PD4-7J6f9j_vH_Y3u93Dbl_eXd3-zwyEUHKpqP674ZtvT5t_0PqAf5XZGN3IdrDjYG00AcN1kkSpY5hfQJvv_JXgxlpjQWpgWHamJ4alcLZlWHpjlOi41G5fDVLVDEuljn14sOYXCT_-ykqczwxLZwXDciK8k867yJ89S68uOgD3Bl61OWloiPvBkoPG2NEJCNMfpCJ7Qb7jGeJGcd0yxD8vjmSdNBowjsbv8-VnT7ekyXJP4DwdoJkWEwFcjy6gkYocCK618VARWGpneA3CWEvCq7eZ2g7ay56cmJdJUF04uFSDpVn5vVNBXaR1nuY8oCJZpXG2Xi3XcdAVq4pWTZMtF0TrNBNiUVViVadZiigqgXkgC4wxS5I4SfI4wTjK04WomwyrNK0bkS1ZFlPPpYrGBCJj20A6N1CRJNkiTwLFK1Juqj6ieF8dbhjimBHD6-ng-DBsMaVYDa1jWaymuD5YvfRqekJztIvtx6Ym4yfpO5gFRk4IQ89tS56l2_N6uV9m4Unq2pxc2LujCAaris77gxvbgCXDspW-G6pImH7u09daTdYcw3J2dyzwdwAAAP__Rk00eA">