junegunn/fzf · error

history max must be a positive integer

Error message

history max must be a positive integer

What it means

Thrown by setHistoryMax while parsing --history-size. The history file size limit must be a positive integer (>= 1); zero or negative values are rejected, including the special case of --history-size 0 which some users try to mean 'unlimited' (use a large number instead).

Source

Thrown at src/options.go:2548

	var err error
	var historyMax int
	if opts.History == nil {
		historyMax = defaultHistoryMax
	} else {
		historyMax = opts.History.maxSize
	}
	setHistory := func(path string) error {
		h, e := NewHistory(path, historyMax)
		if e != nil {
			return e
		}
		opts.History = h
		return nil
	}
	setHistoryMax := func(max int) error {
		historyMax = max
		if historyMax < 1 {
			return errors.New("history max must be a positive integer")
		}
		if opts.History != nil {
			opts.History.maxSize = historyMax
		}
		return nil
	}
	validateJumpLabels := false
	clearExitingOpts := func() {
		// Last-one-wins strategy
		opts.Bash = false
		opts.Zsh = false
		opts.Fish = false
		opts.Nushell = false
		opts.Help = false
		opts.Version = false
		opts.Man = false
	}

View on GitHub (pinned to bd4efa277b)

Solutions

1. Pass a positive integer: `--history-size 10000`
2. If the intent was unlimited history, use a very large size rather than 0
3. Clamp script-computed values to at least 1

Example fix

# before
fzf --history-size 0
# after
fzf --history-size 1000000

# bash
[[ "$HISTSIZE" =~ ^[1-9][0-9]*$ ]] || HISTSIZE=10000
fzf --history-size "$HISTSIZE"

hist_size_ok() { [[ "$1" =~ ^[1-9][0-9]*$ ]]; }

When it happens

Trigger: `--history-size 0`, `--history-size -1`, or --history-size fed by a variable that expands empty/non-numeric then defaults to 0 through the next-int path.

Common situations: Trying to disable history trimming with 0; config generators computing history size from an expression that can be 0; passing --history-size before --history or vice versa is fine, but a negative computed value is not.

Related errors

• unknown action: ${spec}
• invalid layout (expected: default / reverse / reverse-list)
• invalid info style (expected: default|right|hidden|inline[-r
• number of items to keep must be a positive integer
• invalid wrap mode: %s (expected: char or word)

AI-assisted analysis of junegunn/fzf@bd4efa277b (2026-08-15). Data as JSON: /api/errors/92eb5be34eede523. Report an issue: GitHub.