Delve — Interactive Debugger for Go Programs

Introduction

Delve is a purpose-built debugger for the Go programming language. Unlike general-purpose debuggers such as GDB, Delve understands Go's concurrency primitives, goroutine scheduling, and runtime internals, giving developers accurate inspection of their programs without the impedance mismatch that comes from adapting C-oriented tools to Go.

What Delve Does

• Sets breakpoints, conditional breakpoints, and tracepoints in Go source code
• Inspects local and global variables, struct fields, slices, maps, and interfaces
• Evaluates arbitrary Go expressions at runtime
• Navigates goroutine stacks and switches between goroutines
• Attaches to running processes or core dumps for post-mortem analysis

Architecture Overview

Delve operates as a client-server architecture. The backend (dlv) controls the target process via OS-level ptrace (Linux) or Mach APIs (macOS) and exposes a JSON-RPC or DAP (Debug Adapter Protocol) API. Frontends such as VS Code, GoLand, or the built-in terminal UI connect to this API, making Delve the shared foundation for Go debugging across editors.

Self-Hosting & Configuration

• Install with go install github.com/go-delve/delve/cmd/dlv@latest
• Works out of the box on Linux (amd64, arm64), macOS, and Windows
• Configure via ~/.config/dlv/config.yml for aliases, source paths, and substitution rules
• Supports remote debugging with dlv --headless --listen=:2345
• Integrates with VS Code through the official Go extension's launch.json

Key Features

• First-class goroutine awareness with per-goroutine stack traces
• DAP protocol support for seamless IDE integration
• Conditional and hit-count breakpoints for targeted debugging
• Core dump analysis for post-mortem debugging
• Call injection to execute functions in the debuggee's context

Comparison with Similar Tools

• GDB — general-purpose but struggles with Go runtime structures and goroutines
• LLDB — powerful on macOS but lacks Go-specific support
• GoLand built-in — uses Delve as its backend under the hood
• VS Code Go debugger — also powered by Delve via DAP
• print debugging — zero setup but no interactive inspection or breakpoints

FAQ

Q: Does Delve support Go generics? A: Yes, Delve fully supports debugging generic functions and types since Go 1.18.

Q: Can I debug tests with Delve? A: Yes, use dlv test ./pkg/... to debug test binaries directly.

Q: How does remote debugging work? A: Run dlv --headless --listen=:2345 exec ./app on the server, then connect from your local editor to that address.

Q: Does Delve slow down my program? A: The debuggee runs at near-native speed between breakpoints. Breakpoint hits pause execution, which is standard debugger behavior.

Sources

• https://github.com/go-delve/delve
• https://github.com/go-delve/delve/tree/master/Documentation