SamplerCollector crash

**Describe the bug (描述bug)**

**To Reproduce (复现方法)**

**Expected behavior (期望行为)**

**Versions (各种版本)**
OS:
Compiler:
brpc:
protobuf:

**Additional context/screenshots (更多上下文/截图)**

The report contains only the title and a screenshot; no source file, reproduction steps, versions, or expected behavior are provided. Start by locating the SamplerCollector entry point and examining the attached screenshot, then obtain the missing environment and reproduction details. Done means reproducing the crash, identifying its cause, and adding a verified fix and regression coverage.

Written by the indexing model from the issue text.