racevis
Visualize Go race conditions directly in VS Code — without leaving your editor.
go test -race tells you that a race exists. racevis shows you exactly when two goroutines collided, which memory address they fought over, and the source lines that caused it — rendered as an ECG-style timeline alongside your code.
What you get
ECG timeline — see goroutines collide in real time
Each goroutine is a lane. Green = running safely. Red diamond = the moment two goroutines touched the same memory address simultaneously.
Source panel — jump straight to the race
Click any collision zone and see the exact lines from both goroutines, highlighted side by side with a suggested fix.
Usage
- Open any Go project in VS Code
Cmd+Shift+P → racevis: Analyze current package- The ECG timeline opens in the right panel
- Click any red collision diamond to inspect the race
The status bar shows ⚡ racevis at all times — click it to re-run.
Requirements
The racevis binary must be installed and on your PATH:
go install github.com/bramakrishna16/racevis@latest
Verify:
which racevis
# /Users/<you>/go/bin/racevis
Settings
| Setting |
Default |
Description |
racevis.binaryPath |
racevis |
Full path to the racevis binary. Set this if racevis is not on PATH. |
racevis.target |
. |
Go package to analyze. Use ./mypackage to target a subdirectory. |
How it works
racevis runs a two-pass pipeline:
- Pass 1 —
go test -race captures race detector output (goroutine IDs, memory addresses, stack traces)
- Pass 2 —
go test -trace captures the scheduler trace (when each goroutine ran, waited, and blocked)
- Correlate — joins both on goroutine ID to produce a Timeline
- Render — the ECG timeline is injected into a self-contained webview — no server, no port, fully offline
Debugging
If something goes wrong, check the output panel:
Cmd+Shift+P → racevis: Show output log
All binary stdout/stderr streams there in real time.
Source
