facebook/flow · error · Error

Flow not found

Error message

Flow not found

What it means

getFlowPath.ts resolves the flow binary in three stages — configured/PATH flow, npm-packaged flow-bin in the flowconfig dir or workspace root, then bundled flow. If every stage fails (and the bundled-flow fallback also threw), it throws 'Flow not found', meaning no usable flow binary could be located for the workspace.

Solutions

1. Install flow locally: npm install --save-dev flow-bin (resolves via the npm-packaged stage).
2. Or set the extension's flow path setting (flow.path.flows / path.flow) to an absolute binary path you control.
3. Or install flow globally so it is on PATH (e.g. npm i -g flow-bin).
4. If bundled flow failed, check the error above this one in the logs, fix network/proxy, and reinstall the extension.

// Verify a flow binary is resolvable before opening/activating
const {execSync} = require('child_process');
function flowResolvable() {
  try { execSync('npx --no-install flow version', {stdio: 'ignore'}); return true; }
  catch {
    try { execSync('flow version', {stdio: 'ignore'}); return true; } catch { return false; }
  }
}

When it happens

Trigger: Workspace with no flow-bin dependency, no flow on PATH, and bundled flow unavailable (platform without a bundled binary, or the extension's download/install corrupted); also when path resolution is disabled and workspace root detection fails in multi-root setups.

Common situations: Opening a project that never set up flow; CI containers missing flow; proxy/firewall blocking the bundled flow download; node_modules with flow-bin installed at a sibling folder root instead of the workspace root.

Related errors

• Flow version doesn't support 'flow lsp'. Please upgrade…
• Unsupported .flowconfig option `log.file`. The VS Code…
• Attempted to insert a statement into
• Cannot insert array into non-array parent type
• Cannot perform a remove mutation on node of type

AI-assisted analysis of facebook/flow@f88ac94bcf (2026-08-20). Data as JSON: /api/errors/e3cc8571935c06a7. Report an issue: GitHub.

Appendix: source

Thrown at packages/flow-for-vscode/src/utils/getFlowPath.ts:74

    return flowPath;
  } catch (err: any) {
    logger.error(
      `Error loading flow using option 'pathToFlow'\n${err.message}`,
    );
  }

  // 3) if nothing works fallback to bundled flow
  if (useBundledFlow) {
    try {
      const flowPath = getBundledFlowPath();
      logger.info('Falling back to bundled flow.');
      return flowPath;
    } catch (err: any) {
      logger.error(`Failed to load bundled flow.\n${err.message}`);
    }
  }

  throw new Error('Flow not found');
}

async function getNpmPackagedFlow(
  flowconfigDir: string,
  workspaceRoot: string,
  logger: Logger,
): Promise<string> {
  const dirsToCheck = [
    // a) check in flowconfig dir
    flowconfigDir,
    // b) check in workspaceRoot (ignore if flowconfigDir and workspaceRoot same)
    flowconfigDir !== workspaceRoot ? workspaceRoot : null,
  ].filter((v) => v != null);

  for (let i = 0; i < dirsToCheck.length; i += 1) {
    // eslint-disable-next-line no-await-in-loop
    const flowPath = await getFlowBinPath(dirsToCheck[i], logger);
    if (flowPath) {

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