> ## Documentation Index
> Fetch the complete documentation index at: https://codspeed.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshooting

> Understand the warnings CodSpeed reports on your benchmarks, and fix them

## Optimized-out benchmarks

CodSpeed reports that a benchmark **measured no execution time** when it detects
no execution of the code under test. The compiler likely removed that code,
since nothing in the benchmark uses its result.

Keep the compiler from optimizing the benchmark away, then run it again:

<Columns cols={2}>
  <Card title="Rust" icon="rust" href="/docs/benchmarks/rust#preventing-compiler-optimizations" horizontal />

  <Card title="C++" icon="https://mintcdn.com/codspeed/GDLcp8Ny8u4pFbNX/assets/icons/cpp.svg?fit=max&auto=format&n=GDLcp8Ny8u4pFbNX&q=85&s=420e72f7613b61e7f1961ccdd2e4b9bb" href="/docs/benchmarks/cpp#preventing-compiler-optimizations" horizontal width="31" height="31" data-path="assets/icons/cpp.svg" />
</Columns>