go-delve/delve · warning

unable to set breakpoint

Error message

unable to set breakpoint

What it means

updateBreakpointsResponse marks a breakpoint unverified when, even though no error occurred during creation, the resulting api.Breakpoint has no addresses (len(got.Addrs) == 0). Since a breakpoint that bound to no code address is useless, it synthesizes 'unable to set breakpoint' and reports it in the DAP Breakpoint.message with Verified=false.

Source

Thrown at service/dap/server.go:1824

func setLogMessage(bp *api.Breakpoint, msg string) error {
	tracepoint, userdata, err := parseLogPoint(msg)
	if err != nil {
		return err
	}
	bp.Tracepoint = tracepoint
	if userdata != nil {
		bp.UserData = *userdata
	}
	return nil
}

func (s *Session) updateBreakpointsResponse(breakpoints []dap.Breakpoint, i int, err error, got *api.Breakpoint) {
	// TODO(@Lslightly): For DAP v1.68.0, Reason can be set to "pending" when a
	// breakpoint is suspended. But it seems that nothing different happens.

	// Is the breakpoint suspended?
	if err == nil && len(got.Addrs) == 0 {
		err = errors.New("unable to set breakpoint")
	}

	breakpoints[i].Verified = err == nil
	if err != nil {
		breakpoints[i].Message = err.Error()
	}

	// If the error is connected to a specific breakpoint, tell the user.
	if got != nil {
		breakpoints[i].Id = got.ID
	}

	// If we have a file path, update the breakpoint.
	if got != nil && got.File != "" {
		path := s.toClientPath(got.File)
		breakpoints[i].Line = got.Line
		breakpoints[i].Source = &dap.Source{Name: filepath.Base(path), Path: path}
	}

View on GitHub (pinned to a23773e6c3)

Solutions

1. Move the breakpoint to a line containing executable statements
2. Rebuild the target with full debug info (-gcflags=all='-N -l' for dev builds) and ensure the binary matches the sources
3. Use delve CLI (dlv) to verify the location resolves (break main.go:LINE) before using it in the IDE
4. Check substitutePath/remote path mapping so the source file maps to compiled code

// pre-check the line has executable code before setting a breakpoint
// e.g. in the client, only offer breakpoints on statement lines from the editor's
// declaration/statement provider, or verify via dlv: break main.go:LINE

// treat unverified breakpoints as warnings, not failures
if !bp.Verified { log.Printf("bp not bound: %s", bp.Message) }

When it happens

Trigger: Setting a breakpoint on a line with no executable code (comments, declarations, blank lines, non-optimized-out lines); breakpoint in a file not covered by compiled Go code; a location that resolves syntactically but maps to zero program addresses.

Common situations: Users clicking the gutter on struct/func declaration lines or import blocks; breakpoints in files whose build differs from the running binary; breakpoints in generated code that was never compiled; stale binaries lacking debug info for the file.

Related errors

• breakpoint already exists
• breakpoint names that are relative paths are not supported
• call stopped
• could not determine current location
• cannot write a breakpoint to a core file

AI-assisted analysis of go-delve/delve@a23773e6c3 (2026-08-31). Data as JSON: /api/errors/d00225128d893f5d. Report an issue: GitHub.