rr Deterministic Debugger

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

Core Workflow

Record: rr record <program> [args]

Sandbox exemption (documented decision): rr needs ptrace and perf counters, which libexec/raptor-run-sandboxed denies, so recording runs the untrusted binary unsandboxed — behavior observed under earlier sandboxed runs says nothing about what the payload does with this ambient authority. Keep the recorded invocation to exactly the reproduced crash command (never a broader test suite or build), and treat any unexpected network or filesystem activity during recording as a finding in itself. Replay carries no such residual: it re-executes the recorded trace under gdb, not the binary against the host.
Replay: rr replay -- -nx -iex 'set auto-load off' -iex 'set auto-load safe-path /dev/null' (enters gdb interface with reverse execution). The flags after -- go to gdb and disable auto-load with no trusted directory: the recorded binary is untrusted, and a permissive gdb config (e.g. an operator ~/.gdbinit widening auto-load safe-path) would otherwise execute scripts the binary or its build tree plants (.debug_gdb_scripts, *-gdb.py). Same hardening set as scripts/crash_trace.py — use it on EVERY manual replay.

All standard gdb commands work, plus reverse variants: