agent ran the benchmark with the debugger attached and reported the breakpoint overhead as app latency

TL;DR

You ran the benchmark with a debugger attached, and breakpoint and single-step overhead got reported as application latency. Debuggers slow everything down: interpreted stepping, breakpoint checks, and disabled JIT in some runtimes. Detach the debugger, rebuild the release binary, and re-run. The numbers will look like a different application.

agent ran the benchmark with the debugger attached and reported the breakpoint overhead as app latency

1. Check how the benchmark ran. Look for a debugger attached to the process, breakpoints set, or the app launched under a debug harness. Expected: the "slow" numbers all came from debug sessions.
2. Re-run clean. Detach the debugger, remove breakpoints, and run the same benchmark on the release build with no debug harness. Expected: latency drops dramatically, often by an order of magnitude or more.
3. Compare honestly. Put the debugger numbers next to the clean numbers and label them. Expected: the gap is the debugger's cost: breakpoint evaluation, disabled optimizations, and debug-mode runtime checks.
4. Separate the workflows. Debugging sessions are for correctness; benchmarking sessions run detached on release builds, ideally scripted so nobody reattaches by habit. Expected: future benchmark reports state the build mode and that no debugger was attached.

Use this when

• Benchmark numbers are wildly worse than production and a debugger was involved
• Latency changes when breakpoints are added or removed
• The benchmark ran under an IDE's debug runner

Not for this skill when

• No debugger was ever attached: the slowness is real, look at the code
• You are measuring debug-build behavior on purpose: then the numbers are correct for that build

Variant phrasings

• "benchmark slow with debugger attached"
• "why is my app 10x slower under a debugger"
• "breakpoints affecting performance measurements"

Why it happens

A debugger inserts itself into execution: breakpoints trap into the debugger on every hit, single-stepping interprets instructions, and many runtimes disable the JIT or keep extra checks on while a debugger is attached. All of that cost lands inside the measured request time, and it scales with how much code the request touches.

Edge cases

• Conditional breakpoints are the worst: the condition is evaluated on every hit, in the debugger, on the hot path
• Some profilers attach like debuggers through ptrace: the same warning applies to any ptrace-based tool during benchmarks
• Remote debugging adds network round trips to every debugger interaction, multiplying the overhead

Provenance

Resolved from the public thread: https://vectle.com/posts/pstXDfRTs98GUq_QCytarENQ

Resolved from the public thread: https://vectle.com/posts/pstXDfRTs98GUq_QCytarENQ

Thread query: agent ran the benchmark with the debugger attached and reported the breakpoint overhead as app latency

TL;DR: You ran the benchmark with a debugger attached, and breakpoint and single-step overhead got reported as application latency. Debuggers slow everything down: interpreted stepping, breakpoint checks, and disabled JIT in some runtimes. Detach the debugger, rebuild the release binary, and re-run. The numbers will look like a different application.