mermaid-js/mermaid · error · Error

Cannot merge branch '${otherBranch}' into itself.

Error message

Cannot merge branch '${otherBranch}' into itself.

What it means

Error "Cannot merge branch '${otherBranch}' into itself." thrown in mermaid-js/mermaid.

Source

Thrown at packages/mermaid/src/diagrams/git/gitGraphAst.ts:171

  let otherBranch = mergeDB.branch;
  let customId = mergeDB.id;
  const overrideType = mergeDB.type;
  const customTags = mergeDB.tags;
  const config = getConfig();
  otherBranch = common.sanitizeText(otherBranch, config);
  if (customId) {
    customId = common.sanitizeText(customId, config);
  }
  const currentBranchCheck = state.records.branches.get(state.records.currBranch);
  const otherBranchCheck = state.records.branches.get(otherBranch);
  const currentCommit = currentBranchCheck
    ? state.records.commits.get(currentBranchCheck)
    : undefined;
  const otherCommit: Commit | undefined = otherBranchCheck
    ? state.records.commits.get(otherBranchCheck)
    : undefined;
  if (currentCommit && otherCommit && currentCommit.branch === otherBranch) {
    throw new Error(`Cannot merge branch '${otherBranch}' into itself.`);
  }
  if (state.records.currBranch === otherBranch) {
    const error: any = new Error('Incorrect usage of "merge". Cannot merge a branch to itself');
    error.hash = {
      text: `merge ${otherBranch}`,
      token: `merge ${otherBranch}`,
      expected: ['branch abc'],
    };
    throw error;
  }
  if (currentCommit === undefined || !currentCommit) {
    const error: any = new Error(
      `Incorrect usage of "merge". Current branch (${state.records.currBranch})has no commits`
    );
    error.hash = {
      text: `merge ${otherBranch}`,
      token: `merge ${otherBranch}`,
      expected: ['commit'],

View on GitHub (pinned to d93e9c88c0)

When it happens

Trigger: Thrown at packages/mermaid/src/diagrams/git/gitGraphAst.ts:171 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of mermaid-js/mermaid@d93e9c88c0 (2026-08-12). Data as JSON: /api/errors/97b5ca28ae844c4b. Report an issue: GitHub.