Debug & Log

Debugging with Delve

Since Bubble Tea apps assume control of stdin and stdout, you’ll need to run delve in headless mode and then connect to it:

# Start the debugger
$ dlv debug --headless --api-version=2 --listen=127.0.0.1:43000 .
API server listening at: 127.0.0.1:43000

# Connect to it from another terminal
$ dlv connect 127.0.0.1:43000

If you do not explicitly supply the --listen flag, the port used will vary per run, so passing this in makes the debugger easier to use from a script or your IDE of choice.

Additionally, we pass in --api-version=2 because delve defaults to version 1 for backwards compatibility reasons. However, delve recommends using version 2 for all new development and some clients may no longer work with version 1. For more information, see the Delve documentation.

Logging Stuff

You can’t really log to stdout with Bubble Tea because your TUI is busy occupying that! You can, however, log to a file by including something like the following prior to starting your Bubble Tea program:

if len(os.Getenv("DEBUG")) > 0 {
	f, err := tea.LogToFile("debug.log", "debug")
	if err != nil {
		fmt.Println("fatal:", err)
		os.Exit(1)
	}
	defer f.Close()
}

To see what’s being logged in real time, run tail -f debug.log while you run your program in another window.