Raptor rr-debugger

Deterministic debugging with rr record-replay. Use when debugging crashes, ASAN faults, or when reverse execution is needed. Provides reverse-next, reverse-step, reverse-continue commands and crash trace extraction.

install

source · Clone the upstream repo

git clone https://github.com/gadievron/raptor

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/gadievron/raptor "$T" && mkdir -p ~/.claude/skills && cp -r "$T/.claude/skills/crash-analysis/rr-debugger" ~/.claude/skills/gadievron-raptor-rr-debugger && rm -rf "$T"

manifest: .claude/skills/crash-analysis/rr-debugger/SKILL.md

source content

rr Deterministic Debugger

rr provides deterministic record-replay debugging with full reverse execution capabilities.

Core Workflow

Record:
```
rr record <program> [args]
```
Replay:
```
rr replay
```
(enters gdb interface with reverse execution)

Reverse Execution Commands

All standard gdb commands work, plus reverse variants:

```
reverse-next
```
/
```
rn
```
: Step back over function calls
```
reverse-step
```
/
```
rs
```
: Step back into functions
```
reverse-continue
```
/
```
rc
```
: Continue backward to previous breakpoint
```
reverse-stepi
```
/
```
rsi
```
: Step back one instruction
```
reverse-nexti
```
/
```
rni
```
: Step back over one instruction

Crash Trace Extraction

Regular Crashes

After

rr record <crashing-program>

rr replay
# In gdb:
reverse-next 100    # Go back 100 steps (adjust N as needed)
# Now step forward to see execution leading to crash:
next
next
...

ASAN Crashes

After

rr record <asan-program>

rr replay
# In gdb:
bt                  # View stack trace
up                  # Issue "up" commands until last app frame (before ASAN runtime)
break *$pc          # Set breakpoint at that location
reverse-continue    # Go back to last app instruction before ASAN
# Now step forward to see execution leading to fault:
next
next
...

Inspecting Variables and Memory

Standard gdb commands work at any point:

```
print <var>
```
: Print variable value
```
print *<ptr>
```
: Dereference pointer
```
x/<format> <address>
```
: Examine memory
- ```
x/10xb <addr>
```
  : 10 bytes in hex
- ```
x/s <addr>
```
  : String at address
```
info locals
```
: Show local variables
```
info args
```
: Show function arguments

Source vs Assembly View

```
list
```
: Show source code around current location
```
disassemble
```
: Show assembly around current location
```
layout src
```
: TUI source view
```
layout asm
```
: TUI assembly view
```
set disassemble-next-line on
```
: Show assembly with each step

Automation Script

Use

scripts/crash_trace.py

to automatically extract execution trace before crash.