go-delve/delve · error

expected integer value for frame, got %v

Error message

expected integer value for frame, got %v

What it means

The argument to the `runtime.frame(N)` expression construct must be an integer literal (it is parsed with strconv.ParseInt at compile time and pushed as a PushLocal/Frame offset). Any other literal kind — string, char, float, etc. — is rejected with this compile-time error naming the offending AST node.

Source

Thrown at pkg/proc/evalop/evalcompile.go:359

		case *ast.CallExpr:
			ident, ok := x.Fun.(*ast.SelectorExpr)
			if ok {
				f, ok := ident.X.(*ast.Ident)
				if ok && f.Name == "runtime" && ident.Sel.Name == "frame" {
					if len(x.Args) != 1 {
						return fmt.Errorf("wrong number of arguments for runtime.frame")
					}
					switch arg := x.Args[0].(type) {
					case *ast.BasicLit:
						fr, err := strconv.ParseInt(arg.Value, 10, 8)
						if err != nil {
							return err
						}
						// Push local onto the stack to be evaluated in the new frame context.
						ctx.pushOp(&PushLocal{Name: node.Sel.Name, Frame: fr})
						return nil
					default:
						return fmt.Errorf("expected integer value for frame, got %v", arg)
					}
				}
			}
			return ctx.compileUnary(node.X, &Select{node.Sel.Name})

		case *ast.BasicLit: // try to accept "package/path".varname syntax for package variables
			s, err := strconv.Unquote(x.Value)
			if err != nil {
				return err
			}
			ctx.pushOp(&PushPackageVarOrSelect{Name: s, Sel: node.Sel.Name, NameIsString: true})

		default:
			return ctx.compileUnary(node.X, &Select{node.Sel.Name})
		}

	case *ast.TypeAssertExpr: // <expression>.(<type>)
		return ctx.compileTypeAssert(node)

View on GitHub (pinned to a23773e6c3)

Solutions

  1. Use a bare integer literal without quotes: `runtime.frame(-1).x`
  2. Use an integer within int8 range (-128..127); large frame offsets must be narrowed
  3. If you need a dynamic frame, switch frames in the CLI (`frame -1`, `up`/`down`) instead of using the expression form

Example fix

// before
(dlv) print runtime.frame("-1").x
// error: expected integer value for frame, got "-1"
// after
(dlv) print runtime.frame(-1).x
Defensive patterns

Strategy: validation

Validate before calling

func validateFrameArg(cond string) error {
    expr, _ := parser.ParseExpr(cond)
    var bad error
    ast.Inspect(expr, func(n ast.Node) bool {
        if call, ok := n.(*ast.CallExpr); ok {
            if sel, ok := call.Fun.(*ast.SelectorExpr); ok {
                if id, _ := sel.X.(*ast.Ident); id != nil && id.Name == "runtime" && sel.Sel.Name == "frame" {
                    if len(call.Args) == 1 {
                        if lit, ok := call.Args[0].(*ast.BasicLit); !ok || lit.Kind != token.INT {
                            bad = fmt.Errorf("runtime.frame arg must be an integer literal")
                        }
                    }
                }
            }
        }
        return true
    })
    return bad
}

Type guard

func isIntLit(n ast.Expr) bool {
    lit, ok := n.(*ast.BasicLit)
    return ok && lit.Kind == token.INT
}

Try / catch

if err != nil && strings.Contains(err.Error(), "expected integer value for frame") {
    // strip quotes / convert to plain integer literal and retry
    return setCondition(bp, "runtime.frame(-1).x")
}

Prevention

When it happens

Trigger: Compiling `runtime.frame("1").x`, `runtime.frame(1.0).x`, or passing a variable/complex expression where a plain integer literal is expected (the switch only accepts *ast.BasicLit parsed as an int8).

Common situations: Quoting the frame number out of shell habit (`runtime.frame("-1")`), assuming variables or computed expressions are allowed as the frame argument, or pasting code from other debuggers where frame selectors accept expressions.

Understand the failure class

Background: Invalid argument type errors: "must be of type string", "expected X, got Y", and ERR_INVALID_ARG_TYPE explained — this error's family across 15 libraries.

Related errors

AI-assisted analysis of go-delve/delve@a23773e6c3 (2026-08-31). Data as JSON: /api/errors/3dec65df9e63290b. Report an issue: GitHub.