<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/141329>141329</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            compiler-rt build failure on 20.1.5 coming from 20.1.3, on both x86_64 & armv7l (linux)
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

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

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

<pre>
    A bunch of errors like this happen before the build fails.
```
[285*10/480] Building CXX object compiler-rt/lib/xray/CMakeFiles/RTXray.x86_64.dir/xray_buffer_queue.cpp.o
FAILED: compiler-rt/lib/xray/CMakeFiles/RTXray.x86_64.dir/xray_buffer_queue.cpp.o
/usr/local/tmp/crew/llvm20_build.20250524020233.dir/builddir/bin/clang++ --target=x86_64-cros-linux-gnu -DSANITIZER_COMMON_NO_REDEFINE_BUILTINS -DXRAY_HAS_EXCEPTIONS=1 -DXRAY_SUPPORTED=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -D__func__=__FUNCTION__ -I/usr/local/tmp/crew/llvm20_build.20250524020233.dir/compiler-rt/lib/xray/.. -I/usr/local/tmp/crew/llvm20_build.20250524020233.dir/compiler-rt/lib/xray/../../include -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wno-comment -Wstring-conversion -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -std=c++17 -O3 -MD -MT compiler-rt/lib/xray/CMakeFiles/RTXray.x86_64.dir/xray_buffer_queue.cpp.o -MF compiler-rt/lib/xray/CMakeFiles/RTXray.x86_64.dir/xray_buffer_queue.cpp.o.d -o compiler-rt/lib/xray/CMakeFiles/RTXray.x86_64.dir/xray_buffer_queue.cpp.o -c /usr/local/tmp/crew/llvm20_build.20250524020233.dir/compiler-rt/lib/xray/xray_buffer_queue.cpp
In file included from /usr/local/tmp/crew/llvm20_build.20250524020233.dir/compiler-rt/lib/xray/xray_buffer_queue.cpp:14:
/usr/local/tmp/crew/llvm20_build.20250524020233.dir/compiler-rt/lib/xray/xray_buffer_queue.h:21:10: fatal error: 'cstddef' file not found
   21 | #include <cstddef>
      | ^~~~~~~~~
1 error generated.
```

The build is using these options:
```
            -DCOMPILER_RT_BUILD_BUILTINS=ON \
 -DCOMPILER_RT_BUILD_LIBFUZZER=OFF \
 -DCOMPILER_RT_BUILD_SANITIZERS=OFF \
 -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON \
 -DLLVM_ENABLE_RUNTIMES=compiler-rt
```

This ends up succeeding on i686 though.
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJy8Vllv4zYQ_jX0C0FBonw--EG2pK0BH4HtNNl9EShxZLNLk14eOfrQ315QdrJpN1igaFPBsOyZbw4O52LWioMCmKLBDA3yHvPuqM3UMndiivterfnzNMO1V80R6xaDMdpYLMVXwO4oLD6y8xkUrqHVJpAA115IjlsmpI1QnKFhfP3EGRrM6HiAaJbEiJb9cYwGOZ4FvFAHPL-_x7r-DRqHG306CwmGGIdoKUWNaPlk2DOi5XzFvkIpJFhEy-3-3rDn6Gk8rIb9iAtzxVW1b1sw1TcPHqLmfI40irMyWyyLHKXZB-lHtPQ2QKRumES0dKczomVj4DEQ5cOJxlUXnojGdBAPaD-mMU3Tq-aOdf0pVJCUTB0QnSE6w4Q4Zg7gUJpf3CGN0ZZIofwTOSiPSb7L1ov94kuxreab1WqzrtabalvkRblYF9XsdrHcL9Y7TPL7bfa5-iXbVcX9vLjZLzbrHUrz5IWzu7252Wz3IVIdsap2-3xezTfr3T5b76tVNt9udt8Z5Wa7yn4kLxerxV-orVdNVaE0r6rydj0PdqsKk8W_DdtPLjOKPlr_y5dQjfQcMLnrSgSlOWcOiBOntzSvDp4ZDpywByYkq4UU7pkoeMTkjkkZoE_OMEzulCZeeQucnJlhJ3BgMLl7NMIBsc4IdbCY3DXMOvLNsyB5EtYKdSCtAMmJUMIJJsXvYAJQnM5SNMKRlknpjkb7wzHI6wcwwIl9FK45Eg4t89JdzCsNTw2cHXHPZ-hIijwI4zyThDsd3OEgwQF5h6M0afTpBCoou_hLGq0ewFihFSYtF-ygtHWisaTRMgi1IUOc0IpY6N424Jhjb_5vUkzydV7Mbj9hYh1Had5cKiQZXbirHJPV_iNKHJNV-RF6I46J_hiHG_yB2f-uVRRnC4VbIQFfa4Lj1ujT_-9ImiV9lGb_QWP-R6aPKM1oEqzHYdS0zDGJrw0gw4iOGus4hxbR0SVMSjvcaq84ijOMMU0wGs0xoulLT0Hp_EUmLS4gjC-gQfHH9UFxllzM4AMoMMwB_2H-xtn-dUILi33oF2FoW8D63FXYNWBvhPCbh-TzzepmsSy21XbfjZT8dbCgNN-sMRrMg8x7wOViVt5--VJsA7IsfwZ9nWS7n2Hzosxul_tqn20_Fftqs15-_psTy-Wvq6pYZ7NlUW1v1_vFqgga397nOxESFoPiFvsztr5pALr1RCsshuMhdsfQO6Men6Z8kk5YD6bJqD-OB-MkHfaO0yZm_VGf8tEE4gEf1oOGt8mAtXwyGY36k0lPTF-TLO3TZBiN6mRU9xMGYxhCDRPUj-HEhIxCZkbaHHrCWg_TpJ-kdNKTrAZpu42N0jA6Oi6iNCxwZhqESO0PFvVjKayz39U44SRM35z-zbLmDYQj0jhKokFoRuHMXeF2pBTReeDX2h3xpfdgRIeYmdPDSGJEx90mguik542cHp07d7lES0TLg3BHX0eNPl3L7foiZ6PDvhfmZzhDaG_XQz5M6Z8BAAD__-o6YX8">