DTK0052: Launcher Process Exited Before Ready

Message

The "{id}" launcher process exited with code {exitCode} before its server was ready.

Cause

A server launcher built with createProcessLauncher spawns a child process and waits for its server to become reachable before swapping the dock to an iframe. This diagnostic is raised when the process exits first — the launcher races the readiness probe against the process's own exit, so a process that dies on startup (a build error, a missing config, no matching files) fails fast instead of blocking on a probe that can never succeed.

Example

Starting the Vitest UI in a project with no test files: vitest --ui prints No test files found and exits with code 1 before its server ever binds.

Fix

Open the launcher's terminal session to read the process output, resolve the underlying failure, then use Retry on the launcher card.

Source

• packages/kit/src/node/create-process-launcher.ts — the serve launch flow throws this when the process's getResult() settles before onReady resolves.