rr-dash is a time-travel debugging dashboard. You record a program once, and then you can move backward and forward through every line it executed — inspecting hit counts, call stacks, the value of every local variable at every step, a flamechart, and a scrubbable execution timeline.
It's built on rr, the deterministic record/replay debugger. Created by replay.io — the time-travel debugging industry leaders.
"Your program already ran. Go back and watch it happen." Unlike a traditional debugger, you're not re-running anything and hoping to catch the bug — the whole execution is captured, so you can jump straight to any moment.
Record your own program on your machine with the rion CLI. It wraps rr inside a Docker sandbox and uploads the trace to your account.
npx @brett_lamy/rion record -- ./your-programPer-line hit counts in the source gutter
A timeline of every line firing, event markers (syscalls, stdout,
signals, exit), and a playhead you can scrub or play
Watch values — locals and arguments sampled at every step, in sync
with the playhead
A flamechart of sampled call stacks
Live streaming — the trace appears and grows while the recording is
still being extracted