jesseduffield/lazygit · warning

You cannot merge a branch into itself

Error message

You cannot merge a branch into itself

What it means

Returned by MergeRefIntoCheckedOutBranch when the requested merge source refName equals the checked-out branch name (Branches[0]). Merging a branch into itself is a git no-op-at-best and confusing-at-worst, so lazygit rejects it immediately after the detached-head check and before building the fast-forward/regular merge menu.

Source

Thrown at pkg/gui/controllers/helpers/merge_and_rebase_helper.go:524

			self.c.Tr.RebasingTitle),
		map[string]string{
			"checkedOutBranch": checkedOutBranchName,
		},
	)

	return self.c.Menu(types.CreateMenuOptions{
		Title: title,
		Items: menuItems,
	})
}

func (self *MergeAndRebaseHelper) MergeRefIntoCheckedOutBranch(refName string) error {
	if self.c.Git().Branch.IsHeadDetached() {
		return errors.New("Cannot merge branch in detached head state. You might have checked out a commit directly or a remote branch, in which case you should checkout the local branch you want to be on")
	}
	checkedOutBranchName := self.c.Model().Branches[0].Name
	if checkedOutBranchName == refName {
		return errors.New(self.c.Tr.CantMergeBranchIntoItself)
	}

	wantFastForward, wantNonFastForward := self.fastForwardMergeUserPreference()
	canFastForward := self.c.Git().Branch.CanDoFastForwardMerge(refName)

	var firstRegularMergeItem *types.MenuItem
	var secondRegularMergeItem *types.MenuItem
	var fastForwardMergeItem *types.MenuItem

	if !wantNonFastForward && (wantFastForward || canFastForward) {
		firstRegularMergeItem = &types.MenuItem{
			Label:   self.c.Tr.RegularMergeFastForward,
			OnPress: self.RegularMerge(refName, git_commands.MERGE_VARIANT_REGULAR),
			Keys:    menuKey('m'),
			Tooltip: utils.ResolvePlaceholderString(
				self.c.Tr.RegularMergeFastForwardTooltip,
				map[string]string{
					"checkedOutBranch": checkedOutBranchName,

View on GitHub (pinned to c477a2959b)

Solutions

1. Move the selection to a different branch before merging.
2. To update the current branch from its remote, use the pull keybinding (p) instead of merge.

// before merging:
if checkedOutBranchName == refName {
    // no-op guard: deselect or use pull for upstream updates
}

When it happens

Trigger: Highlighting the current branch in the Branches panel (it is the top entry, so it is the default selection) and pressing the merge keybinding (M).

Common situations: Muscle-memory pressing M without moving the cursor off the current branch; assuming 'merge' means 'pull/update this branch from its upstream' — for that, use the pull command instead.

Related errors

• Cannot merge branch in detached head state. You might have c
• Some of the selected branches are checked out by other workt
• You are currently neither rebasing nor merging
• You cannot remove the main worktree!
• Git version must be at least %s. Please upgrade your git ver

AI-assisted analysis of jesseduffield/lazygit@c477a2959b (2026-08-15). Data as JSON: /api/errors/fb6c968025a56158. Report an issue: GitHub.