<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/71532>71532</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Presubmit testing failed to catch basic clang lit test breakages
        </td>
    </tr>

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

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

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

<pre>
    (Breaking this discussion out of https://github.com/llvm/llvm-project/pull/71322)

https://github.com/llvm/llvm-project/commit/ace4489397d17abfb20d36de1404cfbe102401a7 broke a bunch of Clang lit tests (e.g. https://lab.llvm.org/buildbot/#/builders/188/builds/37563).

The breakages did not require any exotic platform, operating system, or build configuration -- it broke everywhere.

The patch did go through a pull request, so presubmit testing should have caught it.

How come it wasn't caught? What can we do to fix it?

@metaflow @tstellar @joker-eph 
</pre>
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