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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - LLVM ERROR: IO failure on output stream: Bad file descriptor"
href="https://bugs.llvm.org/show_bug.cgi?id=41984">41984</a>
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<th>Summary</th>
<td>LLVM ERROR: IO failure on output stream: Bad file descriptor
</td>
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<th>Product</th>
<td>tools
</td>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>Macintosh
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<th>OS</th>
<td>MacOS X
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>release blocker
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>llvm-dsymutil
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>tommaso.piazza@gmail.com
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<th>CC</th>
<td>aprantl@apple.com, friss@apple.com, jdevlieghere@apple.com, llvm-bugs@lists.llvm.org
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<pre>Running dsymutil on a FAT macho binary with > 4 architectures causes IO
failure.
Architectures in questions are: x84_64, i386, arm_v7, arm_v7s, arm64
Everything works fine if -num-threads=1 or if architectures <= 4
I have verified this with dsymutil shipped with Xcode 10.2.x toolchain on
Mojave 10.4.4 and with dsymutil built from source (github).
I couldn't attach the binary to this ticket so I have uploaded it here:
<a href="https://mega.nz/#!39dFyCbD!2EVXvCmySdzFdMfxUhRu0TIRxGEI6n4UvssGWGOuCdE">https://mega.nz/#!39dFyCbD!2EVXvCmySdzFdMfxUhRu0TIRxGEI6n4UvssGWGOuCdE</a>
I have tried to debug the issue. I am by no means knowledgeable in C++ or llvm
but I have noticed that changing the value to 5 here
<a href="https://github.com/llvm/llvm-project/blob/master/llvm/tools/dsymutil/dsymutil.cpp#L539">https://github.com/llvm/llvm-project/blob/master/llvm/tools/dsymutil/dsymutil.cpp#L539</a>
solves the issue. I am guessing this doesn't scale though.
Also, the 'help' text for -num-treads is wrong. It's a binary flag in the
source code. The actual number of threads is always either 1 or max supported
by hardware and never the amount specified on the CLI.
<a href="https://github.com/llvm/llvm-project/blob/master/llvm/tools/dsymutil/dsymutil.cpp#L369">https://github.com/llvm/llvm-project/blob/master/llvm/tools/dsymutil/dsymutil.cpp#L369</a>
there should be an else here with Options.Threads = NumThreads
See also: <a href="https://github.com/Carthage/Carthage/issues/2738">https://github.com/Carthage/Carthage/issues/2738</a></pre>
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