go-delve/delve · error

%d is out of range

Error message

%d is out of range

What it means

`Term.removeDisplay` deletes an entry from the term's list of `display` expressions. The index `n` must be a valid zero-based index into `t.displays`; if it is negative or past the end, the function returns '%d is out of range'. Note that removing the last non-empty entry shrinks the slice, so indices of previously-removed-but-trailing entries become invalid.

Source

Thrown at pkg/terminal/terminal.go:640

	full := proc.LoadFullValue()
	r := *api.LoadConfigFromProc(&full)

	if t.conf != nil && t.conf.MaxStringLen != nil {
		r.MaxStringLen = *t.conf.MaxStringLen
	}
	if t.conf != nil && t.conf.MaxArrayValues != nil {
		r.MaxArrayValues = *t.conf.MaxArrayValues
	}
	if t.conf != nil && t.conf.MaxVariableRecurse != nil {
		r.MaxVariableRecurse = *t.conf.MaxVariableRecurse
	}

	return r
}

func (t *Term) removeDisplay(n int) error {
	if n < 0 || n >= len(t.displays) {
		return fmt.Errorf("%d is out of range", n)
	}
	t.displays[n] = displayEntry{"", ""}
	for i := len(t.displays) - 1; i >= 0; i-- {
		if t.displays[i].expr != "" {
			t.displays = t.displays[:i+1]
			return nil
		}
	}
	t.displays = t.displays[:0]
	return nil
}

func (t *Term) addDisplay(expr, fmtstr string) {
	t.displays = append(t.displays, displayEntry{expr: expr, fmtstr: fmtstr})
}

// rawStringFlag returns the PrettyRawString flag if the config enables it.
func (t *Term) rawStringFlag() api.PrettyFlags {

View on GitHub (pinned to a23773e6c3)

Solutions

1. Run `display` with no arguments to list existing displays and their valid indices, then retry with one of those
2. Use an index between 0 and len(displays)-1
3. Remove all displays with `display -r *` if you want to clear them instead of guessing indices

Example fix

# before
display -r 5
# after
# list first, then remove a valid index
display
display -r 2

// before calling removeDisplay / `display -r n`
func validDisplayIndex(n, len int) bool { return n >= 0 && n < len }

When it happens

Trigger: Running the terminal `display -r <index>` command with an index that does not exist (e.g. `display -r 5` when fewer than 6 displays are defined) or a negative index.

Common situations: Users referring to display numbers from earlier output after some displays were removed; off-by-one confusion (thinking displays are numbered from 1); scripts replaying stale display indices.

Related errors

• %q is not a number
• unrecognized option %q
• index out of bounds
• command not available
• unknown config parameter

AI-assisted analysis of go-delve/delve@a23773e6c3 (2026-08-31). Data as JSON: /api/errors/417bb694916cd574. Report an issue: GitHub.