<div dir="ltr"><br>I recently broke a sanitizer buildbot but I am unable to reproduce the failure. The buildbot that failed is<br><br> <a href="http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/2959">http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/2959</a><br>
<br><br>I looked around in the logs, looking for the config/build commands that would reproduce the failure. The problem is that the bot seems to be using a script which I don't have access to (buildbot_bootstrap.sh). So, I looked for cmake/ninja calls. AFAICT, the bot does a bootstrap and then runs the testsuite with the final build configured with <font face="courier new, monospace">-DLLVM_USE_SANITIZER=Memory</font>.<br>
<br>I tried that locally, but the build dies very early in tblgen:<br><br><font face="courier new, monospace">FAILED: cd /ssd/dnovillo/llvm/bld/tools/clang/include/clang/Driver && /ssd/dnovillo/llvm/bld/bin/llvm-tblgen -gen-opt-parser-defs -I /ssd/dnovillo/llvm/llvm/tools/clang/include/clang/Driver -I /ssd/dnovillo/llvm/llvm/lib/Target -I /ssd/dnovillo/llvm/llvm/include /ssd/dnovillo/llvm/llvm/tools/clang/include/clang/Driver/Options.td -o /ssd/dnovillo/llvm/bld/tools/clang/include/clang/Driver/Options.inc.tmp<br>
==12630== WARNING: MemorySanitizer: use-of-uninitialized-value<br>    #0 0x7f1ea9b01729 (/ssd/dnovillo/llvm/bld/bin/llvm-tblgen+0x8f729)<br>    #1 0x7f1ea9a9cbe0 (/ssd/dnovillo/llvm/bld/bin/llvm-tblgen+0x2abe0)<br>    #2 0x7f1ea9f7b69c (/ssd/dnovillo/llvm/bld/bin/llvm-tblgen+0x50969c)<br>
    #3 0x7f1ea82356ff (/lib/x86_64-linux-gnu/libc.so.6+0x216ff)<br>    #4 0x7f1ea9b01280 (/ssd/dnovillo/llvm/bld/bin/llvm-tblgen+0x8f280)<br><br>SUMMARY: MemorySanitizer: use-of-uninitialized-value ??:0 ??<br>Exiting<br></font><br>
<div><br></div><div><font face="arial, helvetica, sans-serif">I'm not sure how to proceed from here. The bot is clearly building things in a different way, but I don't know how to duplicate it. Is there a  way for me to use the same script that the bot is using? What is the general advice on reproducing buildbot failures?</font></div>
<div><font face="arial, helvetica, sans-serif"><br></font></div><div><font face="arial, helvetica, sans-serif"><br></font></div><div><font face="arial, helvetica, sans-serif">Thanks. Diego.</font></div></div>