DF0052: HTTP Server Failed to Listen

Message

Failed to listen on {host}:{port}: {reason}

Cause

The instance's side-car / shared-server transport binding tried to bind the HTTP server it owns to host:port and the underlying listen() call failed — most commonly EADDRINUSE (another process, often a previous devframe instance, is already bound to that port) or EACCES (insufficient permissions, typically a privileged port). The WS RPC transport is torn down before this error surfaces, so nothing is leaked.

Example

// A previous instance is still bound to 4096:
// await createDevServer(def, { host: 'localhost', port: 4096 }) → DF0052

Fix

• Free the port, or pick another via --port, cli.port / cli.portRange on the definition, or port on devframeViteBridge (@devframes/vite).
• The original node error is available as error.cause — check error.cause.code (e.g. 'EADDRINUSE') to branch on the failure kind programmatically.

Source

• packages/devframe/src/node/instance-shell.ts — the instance shell's HTTP+WS binding throws this when its owned HTTP server's listen() fails.